I have a feeling that the girlfriend that recently broke up with me about a month ago was my true love. I don't think she realized it the way I did but something keeps telling me she was the one for me. Any advice?

If she is gone, she is gone, so you have to move on with life.

Call her and see if she is interested in getting back together AFTER you tell her what a big mess up it was that you stupidly broke up with her in the first place.
She can say okay or she can say no