why do I feel this way

I went from being engaged to feeling like I had everything, called it off because I just couldn't handle the way he treated me anymore. Now I just feel alone, any man that tried to talk to me I just pushed away. I went from having a life plan with someone and now I feel like I'm a useless piece of space, I'm trying to cope I know the things he did and the way he treated me was wrong but now I just feel so alone. I've never been single or on my own and its like I don't know what to do with myself.