Believe me, I know how you feel. I felt like you did when I was younger. I was depressed even as a child -- after i got married, I finally sought out therapy. In fact, I committed myself to a mental hospital for 2 weeks after I had a Mini-nervous breakdown. After I got out, I continued to see a psychiatrist for a year afterwards.
Then thru the years I was in therapy off and on. I'm now on an antidepressant, and have been for many years. It works very well for me, and Lord only knows what would happen if I got off of it!
PLEASE seek out treatment or at LEAST talk to your medical doctor about your depression. You don't need to live like this. Life IS good, with the proper treatment!

God bless and please take care of yourself. It's YOUR turn -- you can't take care of anyone else unless you take care of YOU. Hugs, Lee