How to deal with depression without anyone knowing?

I have had depression for many years now (it got worse after i finished secondary school) and I have always kept to myself everyday. I hardly ever go out and I am so socially akward because I hate who i am and life in general so I avoid others. I never had any real friends during school, only a few classmates i would hang out with and then go home and I just feel so lonely.

Everytime I go out, I see people getting on with their lives, having fun, being social etc... And when I see this I just want to run back to my home. The best way to describe it is that I feel like a ghost. The only thing that keeps me going on are my parents as I know that they care for me and I have hid my depression pretending everything is alright... I used to have suicidal thoughts but never brought myself to do it because I fear death and it's against my religion but living day in and day out, never achieving anything, not being able to make friends, hating the way I look is hurting me so bad inside. If I could get medication for this it would be great but I would have to go to the doctors which I don't want to do... I've had thoughts of drinking and smoking as they are stress relievers but it's against my religion and I can actually value myself positively that I adhere to my faith and beliefs but this depression is killing me :(