Yes, im in your age range; im 18. Its interesting that you mention that you keep making the same mistakes.
After I finally got over those friends and worked through some of my trust issues, I became better friends with another group. After a while I learned to trust them. It turned out to be a big mistake because they ended up sharing certain information with other people, claiming it was for my good.
They may have been right but I was devastated. I think the reason I began trusting them was because its so hard to do everything alone. Sometimes you just want to talk things over with someone.
So know that its normal to keep making such mistakes. Life is all about trial and error.
By you saying that hashem has decreed you live a hard life, I see helpless you feel. Dont give up hope because although its hard now, you still have so much ahead of you.