I know how you feel. Back in the early stages of my depression, I was too scared to even tell anybody about it. I kept to myself. I was always an independent person and believed that I didn't need anybody else and I could get through it. However, since I bottled everything up, things got worse for me. I found myself easily irritated, much more anxious and just hating life so much. My mental break downs became excessive and my mom knew that something was wrong. I did subtly bring up therapy and she did agree to it but never acted on it- mostly due to cultural beliefs. I tried taking vitamin B complex- which has been said to help stress and depression but it didn't do anything for me besides change the colour of my urine.

It just kept getting worse and worse and I was finally pushed to the point where I was firm with my mom about seeing somebody because I could no longer deal with the problems. To this day, my parents don't know the full extent of my mental disorders but it's helped a lot just knowing that I have a therapist and psychiatrist there to take care of me.
I'm just letting you know that this is not an easy thing to deal with on your own, especially if you're feeling so down. Because I waited so long to ask for help, my condition got worse. One major thing was that I started ruminating about things non-stop. I guess to substitute for a lack of therapist, I pretended to be one in my head. It's like a monologue in my head and I can't stop it. I understand that your parents are subjected to cultural stigmas- my parents are to. In fact my dad doesn't even know that I'm currently attending therapy (he said to me that there's nothing wrong with me and if I needed to talk, I could talk to him despite the fact that he's quite ignorant and not comforting at all). Maybe you can start baby steps by talking to a guidance counselor at school.
However, if you are adamant about not seeking professional help and doing it on your own, I guess it is possible too if you have the will. Although I was unable to, I do have a friend who suffered from depression but somehow found herself. A quote that I really like is "When you're depressed, you're fixated on the past. When you're anxious, you're worried about the future. When you focus on the present, that is when you're at peace".
Over the summer, I went on a volunteer trip abroad. It was supposed to be the trip of my life but I was still unable to be happy. But, I did meet a girl who was the most positive/ happy girl I've ever met in my life. When I asked her why, she responded "Well you don't really have a reason to be upset unless you're dying". I know it's cliche but it's true. Some things you ponder over, it's not the end of the world, even though it might feel that way. Just focus on the positive side of it. During the trip, someone stepped on her expensive glasses and broke one of the side of it but she didn't even get upset over it! She wore the glasses anyways as a balancing act and was grateful for the fact that it still fit her face. Something that you can do is keep a grateful jar. Everytime something positive happens, or you're grateful for something, write it down on a piece of paper and put it in the jar. When you're feeling down, just read the things in the jar and see what you have to be grateful about.
I know you feel lonely right now and it's hard not to when you're feeling so down. Something that I've realized is that at my old school, I was so busy wallowing in my own sorrows and self-pity that I didn't even notice all the friends around me who cared for me. I just dismissed them and felt so alone. I couldn't even see them as my friends.
I'm not saying that I have it all figured out- heck I'm far from being ok but I always hold on to the small strand of hope that things will get better in the future. Whether it's due to medication, therapy, or a change in environment. Things have to change sometime right?
Sorry for the long message but I hope it helps you feel better!