First off I agree with what has been said so far.
I do wonder why you don’t want to get any help this year, even though you are feeling overwhelmed by coursework which is below your intellectual understanding? And why do you feel that is an “of course” decision? Would you feel the same if you were deaf or blind?
“Should I just go to a community college and work extra hard?” In my opinion a community college is a good option for most people just out of highschool because you typically pay less money while learning how to navigate college culture and coursework. Plan on that for two years and then transfer in to a typical 4 year university. And expect to work extra hard no matter what, that is the college experience whether you need accommodations or not. The caveat here is that there are more scholarships available for freshman than transfer students. That might be a consideration if you know exactly what you want to do and have the portfolio to get accepted by your target school. That could be plan A and then compare offers to what you would spend by going the transfer route.
It is very helpful if choosing community college route to have an idea of where you want to graduate from and with what degree. That way you can check with the target school on what courses from where will transfer. And until you have an idea of that, stick to electives of interest and the basic gen eds that everyone requires like english comp etc. In some states community colleges have agreements with the state 4 year schools for exactly this purpose. You do need to check which programs transfer to which schools.
“Go to university and request accommodations of some sort?” If you decide on university absolutely request accommodations and stay in close contact with your advisor, the disability department (I lack a proper term), and your teachers throughout each term. You don’t necessarily have to take advantage of all the accommodations all the time. You can use as needed but only if you set them up ahead of time and notified the teacher when the semester starts.
“Wait until I find meds that help me?” I would not wait on this. Meds can help give you the necessary focus to stay in your seat and learn skills. They do not give you the skills you need to succeed.
“Skip college altogether?” Maybe, but not because of ADHD. This option is viable if you have a deliberate alternative plan. Maybe you feel you need more time to mature and discover what you’d like to go to school for. There are structured programs available to young adults for that purpose. They often provide room, board, a small stipend, and funds for education later on. Maybe you just want to work, make money and take a break from academics. No problem with that, but I would apply to entry level positions in larger companies that reimburse for eduction (or a part of it) in fields that you have an interest in even if it is a remote interest at this point. That way when you feel ready you’ll have funding. Maybe you want to enter a particular trade and an apprenticeship is a better option. The trades don’t get the respect they deserve, they are high paying jobs that require intelligence.
check your states employment security website or office, they know of programs for young adults specific to your state
Also there is no law that you have to get a degree in the minimum amount of time. You can accumulate credits before becoming a matriculating student. It is very helpful though to have an idea of where you want to graduate from and with what degree. That way you can check with the target school on what courses, from where, will transfer. And until you have an idea of that, stick to the basic gen eds that everyone requires like english comp etc. Even so, if you make a mistake and take a class of interest in what eventually becomes your major and it does not transfer; it is usually not a total waste of time or money you will just end up with a better grade in the degree program.
“Would accommodations help bridge the gap that my medication used to fill?” Possibly, and if not they would fill a different and very necessary gap. It all depends on what skills are lacking and what effect your meds had. For instance, an accommodation of class notes provided would replace meds if the meds allowed you to actually stay present long enough to take the notes yourself.
“How do accommodations even work?” Have you ever heard of a handicap in golf? https://en.wikipedia.org/wiki/Handicap_(golf) Regular people use them so people of differing abilities can play the game and enjoy doing so. That is what school accommodations do.
“I’ve always felt that it was kind of unfair to ask for extra help, even when I felt it was unfair that my brain was different.” Exactly why it is not unfair.
“Do I even need them?” Maybe not. Interview your friends and ask how much time they spend on homework and what kind of grades they are getting. If you are spending the same amount of time or more and getting poorer grades ask them about their study habits. Maybe all you need is to change your strategy. If that doesn’t seem to be the problem or if even knowing what good study habit’s are, you can’t achieve them whilst trying then yes, you probably need accommodations. At least while enrolled in academics.
“I don’t know what a 504 plan or IEP is, and my mom never tried to get any accommodations for me because meds and taking home anything I couldn’t get done used to work okay.” They are both descriptions of the issues and a plan for overcoming them. A 504 plan is easier to get and usually related to medical issues, but an IEP has more teeth and clout. ADHD can fall under either plan.
Don’t fault yourself or your mom, people accommodate for themselves until the expectations exceed they’re capabilities or their willingness to put in extra effort. It seems you are just getting to that point. It is very good your realizing somethings not quite right and are pursuing a solution. And it is not too late to ask. It is a process and if successful it may be too late to use the accommodations this year or maybe everyone is quick and they are in place for final quarter. If not, you will have the documentation you need for college/university and any other formal program (ex Americorp) you might try.
Go to your guidance department and convey your concerns about getting formal accommodations in place for your last semester and eventually college. If you get push back and probably a good idea even if you don’t ask for an evaluation through “Child Find”. The school is required to do evaluations if parent OR TEACHER suspect a learning disability and request one. This is important because it is very expensive to have this kind of testing done. Ask exactly what you or your mom needs to do to start the process. Talk to your mom and tell her you need her help and this is what the school is asking for.
If for any reason you reach a roadblock with your parents as an advocate, you can advocate for yourself upon reaching 18. And this is not to dis your parents, there are many reasons why a parent might not be able to pull this off this late. Not least inexperience with the process and managing work & home.
It will be very helpful to have a doctor letter stating the ADHD diagnosis and examples of and teacher reports of discrepancies between grades and visible knowledge/ intellectual capabilities. For example tests versus project grades on the same material, verbal output versus written output etc.