especially when starting college, a professional diagnosis can help a lot; i recommend you get one before you start there (if at all possible).
colleges, governments and employers are legally required to offer "reasonable accommodations" to allow you to perform to the best of your ability, but if you do not have a diagnosis, they don't have to do anything.
Think about things like a single room (if having roommates is common, you get a room to yourself), extra time during exams, being allowed to make your exams in a seperate room (instead of the main hall), getting oral instead of written exams...
during work, you might be allowed extra breaks, reduced working times, an upgrade to a 1st-class public transport subscription card...
there are loads of quality-of-life improvements that can be requested, but all of them require an official diagnosis before they will be considered