Relationship advice

So I've never been in a relationship. During my college days, I was really attached to someone and liked him a lot. We were together for about a year. Not relationship together - but it's like when you're close to someone but not given a relationship tag yet. But after one year, I got to know that he was talking to his ex girlfriend and then he left me giving some reasons. I was devastated. Since then, I used to keep pushing men away. Whenever someone tried to come close to me, I kept on pushing them. And that's how I've never been in a relationship. And now that I wish to be in a relationship, every guy around me is either already married or about to get married. I'm 25 Not sure what needs to be done now.