Shady people everywhere

I feel like I can't trust anyone anymore. I broke up with the guy I was with for over 2 years back in February. Then two months later I found out that he had been talking to a girl who I thought was a really good friend of mine. I felt betrayed by everyone because half of the people I was hanging out with knew about it, but no one ever told me anything. Instead everyone kept bugging me about keeping secrets to myself when I never was. I just was't feeling the same anymore. I started to lose myself. I stopped eating. I stopped sleeping. I started getting nosebleeds. I started getting anxiety attacks all over again. I started feeling suicidal all over again. No one seemed to notice anything wrong with me. Why is that? Maybe because I don't show emotion. I keep a straight face half the time I'm around others if not I'll smile like nothing is wrong. But in reality everything is not okay. As of now, my ex is talking to another girl, she was my best friend, but I guess she never was. He took everything from me. People. Trust within myself. The feeling of being happy. I don't know when I'll stop being like this. All the thoughts he brought back to my life kill me everyday. The fact that he was never there for me when I needed someone made me hurt myself in the inside and in the outside.