I really hope that you can take some time off. You can take a leave and return to your school. Work for a bit, volunteer, give yourself time to find a path and then return to school.
ADHD is a serious challenge. There are ways to treat that don’t involve side effects or drug abuse. Please see a doctor to discuss it. You can start with a primary care doctor if the idea of a psychiatrist is too intimidating.
You do not need a full neuro-psych. evaluation for ADHD. Those evaluations are helpful in identifying problems but are expensive. A primary care doctor is probably available at your school or at home and could help you with diagnosis or referral.
The benefit of a psychiatrist is that you would be seeing someone who is totally up on the latest medication possibilities. There are some new ones that are gentler. A psychiatrist in an ADHD clinic at a major hospital is often the best.