Unable to forget bad things. Help.

I am unable to forget bad things that happened mummy life... I had a childhod filled with a lots of struggles..I have been the man if the house as my father was kind of irresponsible due to his drink8ng habit..desire of being a bright student, I had anxieties as my classmates used to make fun if our financial conditions..now m married and have a 3 years old child.last year I left my job as no one was there to take care if my baby when I was in office... I am in depression , I know it..I feel tried all the time, I m irritated all the time, m sad all the time.. sometimes I spend all the night thinking about old memories..I start imagining things, and then react on the things that were not even there..sometimes I think that everything would be fine if I die... I am an emotional person and always help ithers, but everyone takes advantage of me. I want to hain my confidence back..I want to be happy with my family..I want to work again...I dont want to kill myself. Please help.