How do I end my clinical depression without meds or therapy?

Most people who know me don't know that I have depression. It has been about 3 years since I've gotten it, and it is progressively gotten worst. It has gotten so bad that I had cut myself and it made me strangely.. happy. I think if my sister hadn't found out about my cuts that I would've still kept doing it. I think the most thing that triggers my depression is that I'm not like other people. I feel comfortable being at home playing video games then going out to a party or hanging out with strangers. I just want to stay home almost everyday, but recently my sister has forced me to go out and join a dance group. I enjoy dancing, but I usually find my depression stopping me from going full out when dancing since I'm afraid people will laugh at me and ridicule me from it. I also hate when we are finished with dance practice and we have to socialize. I only have my sister there with me and I usually just stand by her and her friends. There are a few people who I want to make friends with, but I don't know if they'll like me. I know I'm wasting my life by being this way, but I continue being this way I WILL kill myself. I'm just tired of being alone and tired of being pressured to being this perfect extroverted girl