I think you are right. First, I really should go for a therapist. It is something I've been looking to do for a while, even just for having a talk or out of mere curiosity. Second, I indeed tend to focus way too much on things that normally do not matter so much. Which just leads to me getting stressed over nothing. Third, I think things will get slightly better once I finally get to have face-to-face courses, especially since I like my new student group (at least from the little I managed to meet them until now), which is always a good chance for making new friends.
Last but not least, I stil have a college year to finish, so better mobilise and feel satisfied at the end that I passed. Especially since I currently do have a set of priorities. I just feel a little lonely, but that can be solved with a bit of effort.