Well I don't want you to implode or give up, you are too young to throw in the towel on life. It sounds like you have a low self image. We can only help our selves sometimes...and I can only say what I do when depression comes lurking around. I get busy..maybe to distract myself from what I'm losing, or missing.
You could do volunteer work...help in schools..mentor kids..visit nursing homes...
I love New York City but then I only visit there and find people very friendly and helpful but I have white hair..

Do you do church?? Many churches have activities to participate in...do you like to read? Where do you walk your dogs?