...and the solution have nothing to do with drawing itself o.o
Today I finally took my time to delete all contents from my DA account(I'm considering posting there all new things, or just continue it being dead account), and since I couldn't find any way to delete all submissions at once, I had to open image after image, and that bringed a lot of memories. I remembered how I suffered with my art style and my art in general being stuck and not improving for long time. Today when I went through all of art I made since 2008, I finally understood what was wrong with my art back then.
I often used it as a way of trolling, or way to critize other people just because I wasn't able to understand or tolerate. I forced my opinions to others through my art in totally inappropriate ways. I often used my art as a weapon. A weapon that can cut really deep. I was such hateful person back then...
Nowadays I feel like I'm doing art mostly for others, to make them smile even if its just for a short time. When I look at it I still see many things that needs to be improved a lot, but at the same time I don't feel bad about it at all. I'm happy with my way of slowly becoming better, and enjoying the journey to become good artist and I hope better person too(I feel like I made some progress at this and since then I don't hate my art anymore (: )

What I wanted to say is, sometimes its not the art itself that is making you unhappy about your creations.

I admire my friends greyfur or rodneyfive whom I befriended loong time ago, when I was new in the fandom - they were with me this whole time, and even if I acted bad sometimes they never really leaved me, and we are friends to this day. Its almost like they knew I can be better person sometime, so they waited for me to become better.