Im just not able to focus at all. Please help

So im a 16 year old student in the uk. I was diagnosed with ADHD and autism abou 3 years ago almost to the day (not a lot of autism just a smidgen) and i take Meikidnet meds to combat the adhd. But more and more often im finding that i really dont like my meds because they just make me sad and i dont enjoy anything. They also make me sweat loads and its just not fun. However, i really need them for school. I did GCSEs and was able to make it through them by not really revising and just going off of common sense and a little bit of base knowledge and i came out with 7,8,9s.

I'm now into A levels and I just dont know how to study effectively or what works well for me. in about 4-5 months i have predicted grade exams which pretty much determine if i will get into university or not and im just so behind. I just got one test back where i got 42% (i never really got below like 65%-70% before) and im getting another back in half an hour which im sure will be terrible as well. Ive always wanted to go to Uni and become a doctor but its just slipping away from me because im not smart enough. I keep telling myself to lock in and all my friends are really smart and can just sit down and work and i just cant and i feel hopeless.

Side story as well i'm just really not good with emotions. I shared a bit of a non-platonic moment with one of my closest female friends and i thought it might be something but honestly that relationship is on the edge of crashing and burning.

Whenever i get advice or a test result the like 2 sides of my brain have an argument and the negative side of my brain always wins and its like argghhh. even now im sitting at my desk typing this instead of working. Could Anybody please help me out im really stuck and just its messing everything up. Any and all responses would be greatly appreciated. thanks.