I experience problems with being assertive. To me assirtiveness would be one of the best skills to learn.
I do not believe that eliminating the aggressors or everyone in your life that makes you feel hurt or constantly belittles you is a good idea. Sometimes you just don't have a choice. I personally have had problems with my partners friends. Obviously friendship is important and you don't want to be that person that gives an ultimatum. Last year I was going through a really rough patch and didn't have anywhere else to go, and so I went to my partners place because it was the safest place I could be (or so I thought). All I did was cry and his housemates said that they didn't want me to be around the place when I was like this. Instead of talking this through with them personally, I got upset. I stormed off in a big huff because my partner was not sticking up for me. Then as I was making my way home I decided that what had just happened was not good enough. This is where I made the bad move. I decided to go back to the apartment and stick up for myself because my partner wouldn't. I wanted to explain to them how important it was for them to be understanding on this because I had no where to go. Instead I went in and screamed at the person that had unwelcomed me because I was so angry that I had been treated the way I did. This made me feel worse and made the situation worse. Rather than being assertive I became aggressive because I could not explain what I needed to and automatically assumed they would not understand. Making assumptions is one of the worst things you can possibly do but I just still to this very day have trouble not assuming that people think the worst of me. Because I never had the chance to go over this with the person I still feel hurt to this very day. And he has probably forgotten about it but I am in pain.
I hate not being assertive and once I learn to be I hope that in future these sort of things will not happen again.
It is difficult though when you do not trust anyone - hopefully that will also improve with time.