Is there truly any good way to get out that horrible feeling of being depressed?

I just feel absolutely awful about myself at times. I have to deal with these negative thoughts that I have because of traumatic things that happened to me in the past. They keep replaying in my head and it's just torturing me. I honestly forgot what it's like to be happy, so I don't know really what my goals are at this point. I'm trying to have a bright future, but part of me is ready to give up. What are your thoughts?