Explaining Dropped Semester and Mental Hardship

[FlyingGoldFish]

Hi everyone,

I am applying to STEM graduate programs, and I am gathering materials of my previous accomplishments to work on my applications for this season. I have a major concern of my transcript. Unfortunately, I was not a stellar student, and I dropped some classes on the way thinking that I would success if I take it again. However, that was a mistake. I should have kept on going, and now I am worried about the admissions committee looking at my transcript thinking I won't be able to do well in their classes.

My overall GPA is 3.2, and the major courses GPA is 3.1. I kept convincing myself not to self-compare to others, and maybe I can shine on my research experiences (2+ years), presentations, and manuscript in preparation for one of my research works. However, the problem is that I dropped an entire semester once because I was suffering Major Depressive Disorder. I've seen some people here who experienced similar mental hardship, and I feel for them too. I do have a letter from my school therapist explaining all the situations that I was going through, but I'm just not sure how to express this hardship on my applications. After researching, I got a feeling that ad com don't really want people who show mental instability. I am much better now, and I learned how to recover, get better, keep running. Another thing is that, after that dropped semester, it's not like my grades were succeeding. They were consistently B's and some C's. The only A's that I got were research courses, intro stem courses, and other humanities. It was difficult for me to manage taking 5-6 courses and research on top of that, and also trying to graduate on time. 

Since grad schools usually have 2-3 courses, I am confident that I can do better when I get there. I was thinking maybe I can convince one of my professors to mention about my mental hardship in LOR and that I can do better. I don't think I should have the letter from my therapist sent out because that might just seem like I'm asking for sympathy. Does anyone who had similar experiences, or has known a friend who went through similar?