What should I do about my girlfriend?

So me and my girl have been together for over a year now and everything started out right and I was very happy. I have never opened up to someone so fast and gave them my heart so quickly because she just felt like the right one for some reason deep down inside me. Going back to our one month i received a picture message of her teasing me but then i noticed that it had two other numbers in the message. I confronted her and she started crying saying that she was so sorry because she never trusted a man before. I said if she wanted to continue to be with me that all that would stop and she promised it would. After a few months everything was all good and i trusted her. Later on after we were together for like 4 months i started getting my 6th sense getting itchy. She came over my place and when she was asleep i looked at her phone and she was txting both men saying whole bunch of bs like i miss you and things of that nature. I found out that she has been talking to the two men a whole year before talking to me and it seems like she still had feeling. We got into a big fight cause i looked in her phone and i confronted her which i know was wrong to look in the phone but i just had to know. After that i just went about my Business and she said she was done because she loved me and she didn't want to loose me. Like 2 months after that i got that 6th sense feeling again and when i visited her i seen in her phone that she was still talking to one of them in particular and i found out that she was playing both the men the past summer but cared more about this one. We got in a fight again but i still didn't break-up with her. After that i always belived in giving someone your all but she hurt me three times so i started talking to other girls but nothing like how she was just for fun since it seemed she was doing that. now at one yr she was over my place spending the night i had the same 6th sense feeling and looked again at here phone. Now they were texing each other that they love each other and she didn't want to let him in her life because she didn't want to get hurt? Also there is a new guy who she has been calling between talking to me talking like every other day for like an hour. They txt things like sweetie and baby how we txt each other. Don't get me wrong i know she is in love with me because she always tell each other how we are going to get married and talk about possible places to start our lives. I know she is not cheating physically but emotionally is just as bad. We are so serious that we are even willing to go against our families to be with each other. But i don't know what to do at this point? I love her dearly and she loves me too but she keeps talking to other men and to say that she loves them? I don't what to get even more serious just to get left when its all said and done. My heart is telling me that we should be together but I just keep getting this feeling like i don't know? Can anyone give me any advise on what i should do? Will she eventually grow out of this or if i stay with her will i just keep dealing with this?