I would go back to my GP if I were you and ask for an evaluation for ADHD. Tell them the problems you are having and how much it is affecting you.
Only you know what does or does not work for you. So try to work out a plan of action with your doctor. This could be a lengthy process of trying different medications so maybe try to keep a daily diary and note down what you are taking and when, as well as how you are feeling or coping. See if you can find a good pattern.
I remember being 27 and feeling utterly lost. Apart from having ADD, it is an age where you question the direction your life is going in and what your purpose on Earth is? Your brain also reconfigures around this age, which doesn’t really helps your feelings of not knowing who you are.
Do you have anyone you could talk to about this?
Perhaps your life needs to change? What worked for you as a young adult may not be what is right for you now.
Try it out by starting small. Look around for inspiration. Get as much support from any friends or family as you can. If you don’t have friends or family, ask your doctor to recommend a support organisation who can help you. There are lots of charities doing good work to support people through difficult times.
You’re not crazy. Just a person who needs some help and care. Be kind to yourself. x