You sound like a positive, empathetic and dynamic person who has put a lot of energy and enthusiasm into your first semester of school and for that you should be very proud. Though it has been a positive experience so far don’t underestimate how much energy it must have taken for you to settle in and it may be that your body/mind is having trouble switching down a gear and going into the relaxation mode that you supposedly should be experiencing at the moment. I find the same problem and I think that when I don’t have to keep going at such a pace my mind has trouble slowly down and this is when the over analysing takes over. It’s almost as if my mind has to do something to keep busy so it starts creating it’s own “entertainment”.
If you are back at home after having been away for a while are there any old friends you can reach out to and catch up with? Also ,maybe you should think of this time as a chance to recharge your batteries so that you can go back to school with the energy and enthusiasm you started with at the beginning. Maybe going for a run, doing yoga or going for walk might help your mind start slowing down. Or having a bath, painting your nails, visiting a museum or gallery on your own or with a friend, or meditating might help.
The fact that your mom suffered from depression is not an indicator of how you feel. My mum had depression and other problems throughout my childhood and adult life. I think my ability to “over analysize” helped me understand why she reacts the way she does to different situations, and that empathy helped me understand that I am a very different person and would never react in the same way. By working this out it has made me stronger and more confident about myself as a positive person.