At my university, students can elect to get a medically-excused incomplete that enables them to finish a semester on their own time. That may not be obviously offered at your university, but you should look into things along that line.

Before I knew I was BP, when I was your age, I used to push myself to try to keep up with everyone else even when things happened that got in the way because I assumed that was my only option (almost 10-15 yrs ago now). There is increasing awareness of mental health interfering with academics at basically all universities. As faculty, we discuss it frequently (I'm not out so always feel awkward about these discussions). I believe that if you speak to student services, mental health, even if those people are quite few at a small school, they will offer you good options. Chances are your math and physics professors are not aware of these policies so you should see whoever you can first who acts as a student liaison to have them help negotiate with you what can be done about your classes.

Hope that helps.