Beginning to finally be comfortable with who I am

Hi people of Giantbomb. My name is Brian and I'am currently a college student residing in Colorado springs, Colorado. For the longest time I have struggle with the whole concept of self worth. Many days I have questioned why I get out of bed in the morning. Why do I even exist and whats the point of it? Other times i'll feel fine. Things aren't going terribly for me and really haven't been other than Lyme disease, but I still struggle at times with the concept of success. At times its been hard to see even where I'm going in my life. 
I think as college rolls on i'am just now getting used to myself again. Some days really feel like nothing more than dreams. It can get depressing after a while, but I'm getting back to being on the positive side and in doing so things are going better. I'm socializing more slowly, but surely.  I'm helping friends with their problems whether simple classwork or personal and thats fulfilling. Thing is I felt gloomy this weekend and it threw me off. Depression hit and its hard to battle. Watching the whole season of Louie didn't help either. Things look better already though and its very nice to get reassurance from friends and people around me in general. Things are starting to look up again and with time and self awareness things can stay that way.
Have you had moments of darkness and gloom?  
What did you do to fight it? 
Do you still feel at times that you don't know what you can contribute to the world?