Might be under depression. Of mind.

I think I am under depression. I don't do anything productive throughout the day. I am someone who used to sleep 6-7 hrs/day and would work quite a lot. Now I sleep 10 hrs/day and do nothing. I have started eating a lot as well. I find it hard to be happy these days. Whenever I am not occupied, I start thinking about my failed relationships and the reasons and answers for it. Seeing other couples irritates me and makes me envious of them. There's this great feeling of disappointment which I have because of my failed relationships that I can't shake off. And it's affecting me a great deal. I have college exams to take care off, I have my own startup which needs time but I feel I have lost the ability to focus. Things are also not great at home as well. Since I am the eldest child, there are a lot of responsibilities on me, which I have taken care of before, but now I just don't seem to have any patience towards anything. I feel lost, helpless and have lost my peace of mind.