I’m so sorry you are experiencing this. It sounds like you are describing me many years back as well. Motivation for many of us is a big problem, and like you said it feels like trying harder has the reverse affect…because it does! I tried many meds and supplements over the years and finally have found quite a bit of difference in Wellbutrin. I cant say it is perfect, but what a huge difference to have the adrenaline I need to get going. Only then did years of learning techniques pay off for me. I still lose time if I am not careful, but my brain needs some off time too! I could still use a bit of Ritalin or some natural things like ginseng sometimes help in order to focus on a task, but I have been accomplishing more than ever before in my life.
I periodically forget my medication and definitely feel the difference. I would get back on whatever you said was working for you. Even if you forget sometimes, it is better than having no hope of a productive day. Put a reminder at the top of every calendar day. Have it also send you a notice on your phone. I usually have back up plans but still I was 2 hours late for my car appointment this week simply because I forgot to look at the calendar first thing in the morning! They were very good about it.
My husband also helped me clarify my misconception of time for specific tasks. For example, I thought it only takes me 30-40 minutes to get ready in the morning to go out, however it really takes an hour. He had my permission if I got sidetracked, to say “is that essential right now?” And I found myself asking the question at times too.
Anyway, don’t give up! The articles in ADDitude magazine have been very helpful for me in many cases too!