OP - isolation - great to hear you are working and living on your own! (if I understand you right) - that is quite an accomplishment!!
Some people don't manage to do that even if they/we went to university!
What you need is hobbies! Explore and try new things.. If you enjoyed things in the past (like any sports or crafty/artsy efforts etc) see if you might like them again? Maybe sign up on a course to learn a new skill or language? Or any adult ed evening classes?
If you like travelling and trips, and hanging out with friends - yup, set plans to travel and see other friends.. Or plans to make new friends...
What about music/concerts/festivals/events? Could you enjoy some of that too? They can be low-key like open museum lectures, or cafe poetry readings/book presentations etc.
'Socialising' doesn't have to be a dirty word, you know!! It can be FUN and meaningful, like volunteering, helping with a charity or eco organisation, and you can meet interesting and nice people and new friends this way too!!
IamThisOne, transition from college to 'real world' can be scary - it's survivable though!!
Some people find work better than studying!! (Just ask Black Puma)
Some like studying better than work - it depends on the work and what you study and who with! You can just explore some things and take it as 'learning experience'?
ITO, please get your doctor to adjust or change meds, and get some CBT/counselling or such?! We do care about you, even if you don't!