How do I make myself happy? how do you fight depression?

everyday I wake up with like pain in my heart, I'm just not happy. I think having no job has a lot to do with it. I'm discouraged I've applied to 150 places and no call back. I went to store to store to apply and nothing. I just feel broke, no money, no career nothing. I wanna focus on applying to grad school but I'm scared my grades from college won't be good enough to get in. I also have no love life. virgin, never had a boyfriend never been on a date. the one guy I liked in college broke my heart and played me. I've also seen a lot of friends come and go. I don't believe in true friendship anymore. friends don't stick around after college. when you need a friend the most, they turn away and don't care about you.

I'm just depressed and suicidal. I don't think my life will ever go anywhere and I don't think I will ever get married.