I don't seem to be able to get over my ex of 5 years relationship

Hello, So i have been dating this girl for five years. She was 19yrs at the time we started dating now she is 24yrs. I was 22yrs when we started and I'm 27yrs now. I'm not saying i was the perfect guy but i did my best, i gave my best shot at the relationship, and i thought the relationship would lead to marriage. Heres the story, One year into the relationship i started noticing some bad traits i didn't like. I started seeing her with different types of guys, some she would visit/be with till late hours and of course i was jealous, not like i was insecure. I spoke about it a couple of times because i wasn't feeling respected. Let me cut the whole story short. Within four years of dating her i was double dated like four times (i know you mite be like why didn't i walk away) truth is I'm bad at walking away from people in my life and i don't know how to give up on people i truly love. I kept forgiving her and giving her another chance and i felt maybe she was young and probably needed time to grow up. I guess i was wrong. Last year 2018 December i found out she was getting close to like 3 guys and it kinda got me worried at least from my past experiences with her and i spoke to her about it, she didn't want to open up at first but later did and was like, she's just keeping them for fun. I asked her to keep away from them for the sake of our relationship which she promised to do. Two weeks later she was going on dates with one of these guys i found out and i broke off the relationship. Not like i have given up but i thought breaking up would scare her and make her think of how far we've come but again i was wrong. During that period we kept talking even though we were not dating, we still hooked up and stuff. Then January just as i was planing on a come back i found out she's already dating that same guy i broke up with her for, the main cause of our brake up. Like Barely a month after we broke up. That made me feel really bad and i felt maybe she never loved me all those years. She didn't want me to know she was dating already, but i heard some news and i went extra miles to find out. Now she's saying she still loves me and she doesn't want to lose me but she cant break up the relationship with other guy because they just started and it would be weird the brakes up a month old relationship with the other guy. I couldn't stick around and wait while i watch the girl i love be with someone else, so i tried to win her back, i cried, talked , i messaged like a million times, called etc But nothing good came out of that, all i got from her was i should give her some time. I couldn't bare it and i decided to walk away. Now its been like 2 weeks, 3 days i started the no contact rule ( for 5 years this is the first time we haven't spoken for two weeks plus ). I know i'm supposed to walk away but i find myself thinking about this girl everyday almost every minute. I keep wondering what she's up to whether or not she's happy with the new guy or they still together. ( i know i'm not supposed to do that) I know i'm a good looking guy and a lot of girls want to be with me ( good girls i know of ) but my mind is just on this girl that keeps treating me poorly like i don't mean anything to her. I really need your help , i know its just been 2 weeks 3 days but i'm loosing my mind, i thought she would have reached out to me by now. I have been tempted to text but i have been trying to stop myself from doing that. PS.. She knows me quite well enough because all through our relationship i have always been the person doing the chase, even when she offends me i still chase her and try to settle and make things work. So i don't know if she's expecting me to never be able to walk away from her or find someone else?? Because she seems comfortable with everything that is happening and i seem to be the only one going crazy over here, and i really don't know where to start from with another girl. I'm scared of trusting any lady. I'm just in a wreck right now. Please i need your advice on this Sorry i'm bad at writing long explanations. I skipped a lot to make the story abit short. Thanks so much for your anticipated advice.

Thanks so much.