Absolutely true. And I don't want to call anyone grasshopper, lest I get old fogie back, but it can take years to reach a manageable solution. This will not be sorted in a few months, unfortunately.
And I did not say that lightly. I KNOW it is a big deal if it ends up taking years! That said, from what I read, the majority of people that need it DO find something that works, and if the prescriber is a good one, for these people something is found within the first 1-3 that are tried. Playing the odds,
@fisbp, it is VERY likely that you're in the group who will find something that works. That's why I recommend you, *as an 18-year-old*, continue trying with the outside help for longer than a few months.
Besides that, I wish you would not give up on yourself just in general. You have a lot going on and that is obscuring your true capabilities. Plus you have not yet learned the life (or study) skills and habits that would help you. New behaviors CAN be learned. If you cannot get a coach or take test preparation classes, you can seek out materials on your own that will break it down for you into small steps that you can do. But in your shoes, I would ask the therapist for some direction in this area. If they will not help you themselves (and they might) then they will certainly be able to find you a good resource (as in a book or something online). Very many people need this kind of help. You're not alone. If you learn this stuff now, it will help you a lot as you go through life as an adult.