Bad Choices

I am not sure what my problem is but when faced with a decision about a relationship I usually make a bad choice. Twice in my life now I have been faced with making a decision between two guys that I was started to date. I personally find it really hard to juggle two guys that I am dating at the same time, so at some point I am forced to make a decision. Both times, the choice that I thought was correct, I thought I was following my heart, ended up to be the bad choice. I am not complaining or wishing that I could turn back time, however, I do want to know how to make a better choice, how to know which guy is better for me. I am just tired of starting a relationship and having the person not be the right one for me. I don't want to me the girl that has a 100 boyfriends and never settles down. HELP! haha.