Putting my daughter before the love of my life!

I am 43y male and met a beautiful, clever, wonderful 32y 2 years ago that 'got me' in a way no other woman had ever managed before. We shared magical times & both helped each other through similar difficult divorces.. I have a 5 year old daughter and went through a long and arduous legal process at huge emotional and financial cost.

The problems started when I wasn't prepared to compromise my time with my little girl over my girlfriend. I matched our weekends with her children and it worked wonderfully but continual fighting, comparisons of affection, showing too much 'clinginess' to my daughter & fall outs resulted in swapping back the weekends. Don't get me wrong this girl meant the World to me but it seemed unnatural to not devote myself to being the best Dad I could be.. A result of this meant I continually pushed her away and months of falling out and getting back together. It scared me and I never gave her any indication of a future despite her concerns. (Home/marriage/kids!)

Three months ago I found out she had been cheating on me with an old boy friend & although I don't know what happened I am pretty sure they slept together. We broke up for good but I just cannot get this girl out of my head and have returned looking for validation and to try and repair what we had but have simply resulted in hurting myself more... I know she is desperate to be loved and text's/calls me all the time telling me such and I so want to make it work because I fear I will never find that connection again or find a woman that made me tick like her..

I was always faithful to her despite her continual concerns that I was being unfaithful and after reading up about stuff realize she was very codependent insisting on being by her side all the time, keeping in touch via text and calls & frowning on any female interaction from my part.

Here's the best bit....& she told me this! She was straight on Tinder and hooked up with a guy within 5 days and told me filthy intimate things that they did together. She called me last weekend to say she was going for a day out with him but didn't want to & she wanted me. Being a sucker and not wanting anyone else to have her I spent 3 days with her in a vain attempt to try and resolve everything (again!) & again due to me requesting she showed me dozens of intimate messages (some slutty!) shared with her and different men on Facebook & SnapChat. She said she has slept with 2 men since our split but I suspect 4! She also told me she had a sexual experience with one of her girl friends months ago & attacked me in a fit of rage/jealousy one night! WTF! Sounds mad even writing this but she was fighting for me when I was pushing her away.

I know she's doing this to make me feel jealous and simply moving on with her life but I have completely lost my compass & sanity over this. She has more male friends than female, has a colorful sexual past but has said to me if I can make that commitment she will agree to move away. close all her social media down and start a new fresh life with our girls.

I know what the correct answer is here & feel a little embarrassed even posting this but it kind of helps tapping away on these keys getting it all out. I have been ill the last three months since we split, lost weight, been unable to concentrate on my career or family despite looking after myself and doing all the right things.

I know you might think seems like a joke but I still keep getting these nagging doubts that I'm losing the best thing that ever happened to me if i show her what she wants-commitment!

Feel a bit of a laughing stock even reading over what I have written but here goes...