Attracting the wrong type.

I need to get this off my chest and here's the only place I can really talk about my feelings.

My first ex made me fall in love and then pulled away and got distant. I later found out that I wasn't his only boyfriend and he had been cheating the entire relationship. Obviously it ended after that

I then dated a lovely person, normal and friendly. Yet I had no feelings develop for him so I had to leave it.

My most recent partner has pretty much treated me the same as the first. I fell in love, he pulled away, dumps me. Within a few days he's seeing someone new. I strongly believe it was happening before he left me.

Honestly I have a feeling I'm going to be stuck in a vicious cycle of liking guys that are truly awful people, because I'm too trusting and naive when it comes to feelings. Has anyone got any experiences similar, and can anyone recommend certain things to look for in a guy that are either red or green flags