This is a really hard question. I was in a terrible group of friends, and I got really depressed because of that, to get better I needed to completely change where I was, I know that changes are really hard, but sometimes they are the best answer.
Another thing that I learned literally yesterday, is that friendships are always different, don’t have the same expectations that you have for the last group of people. And be aware that you don’t need to completely share all details of your life with them (same goes other way), just be comfortable and be yourself. <3
And if people are making you sad over and over again for the same reasons: they are not your friends.
I don’t think I really answered you question, because I also struggle to make friends, but I hope it helped :)