Am I losing my brain or is it just ADHD?

I hope it doesn't sound vain, but I used to be called a prodigy. I used to be great at everything I touched, as long as it did not need group activity. I've been diagnosed with OCD and ADHD at childhood and severe depression in adulthood. My psychologist says my case is way too complicated to be just depression, OCD and ADHD. But nonetheless, I've lost interest in every activity I used to be good at, and now I don't seem to be good at them anymore.
I used to have this huge crush on someone and after it hit me that they don't like me back, I couldn't eat well and it's a long story but I became like 5kg underweight after being normal and having chubby cheeks, in like 1 month. I'm suspecting it affected my brian. After that, I couldn't concentrate on things and I kept forgetting I had my phone in my hands so it fell down and broke twice.
Even in university, I keep failing my classes despite studying hard and my friends and classmates ace them with no effort. I keep asking stupid qusetions in clas too! I'm studying to be an Engineer and sometimes I think maybe it's just not something I'm interested in in general or something I'm talented in. But I used to be so good at maths and technical stuff, and I liked it so much! I wonder if the lovesickness damaged my brain or is it the pills as my mom says, the depression as my psychologist says, or the ADHD?