I'm a 18 year old male. I have been battling depression for some time. It feels like even though I want help I don't know where to look. 

Iv tried natural medicine, exercise, proper meds and therapy. 

The most recent summer was really tough. My moms always been kinda mentally abusive but when times got really tough she was always there. This summer times got really tough but she wasn't there. She ran away from me(this was before I was 18), told me to get over my depression and said if I didn't id tear down her and my little sister with me. 

I really trusted her with sensitive stuff like that. It got to the point where I was heavily contemplating suicide and was self harming(this was the peak of it). 

I'm worried now cause things have calmed down between us. Yet the depression is coming back and it feels like its coming back worse. Self harming and suicidal thoughts was the peak of my most recent depression. Now its the starting. 

I know I can't go. I have a gf who would take her life if I did and it would ruin my little sisters life. 

But it feels like I can't trust anyone I could before. My gf did nothing wrong and I felt I didn't trust her. It just feels empty. She brings me happiness but I'm worried I'm not enough for her. 

I feel so angry at everyone except her but its semi long distance( we can only see each other for like max 2 days a week as we live about 2 hours away from each other). 

I feel like everyone has let me down. 

Any advice cause quite frankly I don't know where to turn.