Hey everyone thanks for opening my post. I'm giving this a shot because I could really use some direction.

I've been in a relationship for a little over one year now, with a beautiful and successful single mother, who is in her early 20's. I am 29 well established in a good paying job. The past few months have been very tough for us though.

She still lives at home, and about an hour away. We work together. The father sees her 2 year old every other weekend. The father and her do not get along at all, and in a custody battle constantly with lawyers involved. Tensions began to arise when I found on her cell many months ago she was texting a male she met from her gym. She was using him as a source of venting about me when I did not do certain things she disliked. Some were legitimate, such as having to cancel plans or not use my free time to be with her and her daughter. Some of this was because I work random overnights, and need to sleep in the day. She was of course upset i went through her phone, however I had suspicions she was talking to someone else. I was wrong, however I found this. She was contacted by her ex (not the father, but a boyfriend of 5 years who took her child under his wing when she was first born-he was heavily integrated). I found again on her cell she was talking with him asking him to meet up and acknowledging her daughter missed him. I told her there is not room for me and him both for her daughter as this isn't healthy for the little girl. 3 months later i saw on our shared phone bill they were having late night talks up to an hour. I ended things. She admitted she did it for these reasons:

1)she states they never made physical contact
2)after 8 months her baby didn't seem to like me, and I wasn't doing enough to take on an active role. Her family and friends warned her about me, especially because per her mother "children are good judges of character."
3)I wasn't a very good boyfriend and did not meet enough of her needs.
4) she needed closure with him. She doesn't want to be with him, she wants me.
5) her mother was inviting him over in the day time while both of us were at work, and having him babysit her daughter.
6) her mother was reaching out to him for emotional support for a recent death in the family.

All of this occurred around the time of her grandmothers death. Although I knew of this, I still stayed to provide support. She sent me away. She asked I watch her child for the funeral though instead of having me there. She said her family didn't want me there since I left her during such a hard time.

I found out later her ex was at the funeral.

She begged me to come back and that she did not want him. That she wanted me to soul search and help improve myself and she wanted to be there with me as I did it. She also listened to me and my concerns why I was unhappy with her many times. She chose not to bring her child around me following all of this. I agreed. I care very much for her child, and was starting to get very close. However, i disagreed with a powerful situation: Her child was being raised by her mother because she had to work. The mother has a strong personality and took over the care. She tells her how to raise the child for as long as she lives in that house-but can't go anywhere because she's too "irresponsible" to be on her own with a child. She constantly yells at her for not getting an abortion, and frequently warned me to run for the hills because theres something "not right" with her daughter, and that she's "no good".

My argument was this
1-How can i find a place in the childs life if her mother dictates and rules over how the child is raised?
2-How can i find a comfort zone and finding my place, if she's still living in her parents house?
3-Significant others cheat, likely because their partner is failing at providing something. I took responsibility for it, and agree that I can use this experience to look inward and improve myself.
4-I do however feel that she fails to take responsibility for what she did, and would rather blame it almost completely on me for "putting her in that position".
5-I hold, now, a deep resentment for her mother. 1-because of how horrible she speaks to her daughter, and how she was allowing the ex around behind my back.
6-I resent how her mother dictates how the child is raised, and if anything goes wrong with it, yells at her daughter blaming her for being abad parent. However I have a mixed feeling, because I know her intention is only to do what she knows best- to be a mother and take on that role.

I recently broke up with her again after i brought her to a wedding, and she didn't want to stay overnight with me because she doesn't like how i hold things against her mother. This was brought up a day earlier when she admitted she wants another child soon-my response "not while your in that house, I'm not going to have your mother raise my kid"

I broke up with her at the wedding. Bad timing i know. She left, and went out with a guy that just gave her his number. She didn't contact me until 4 in the morning. she asked me the next day if I would take her back. I was too upset about her going out with someone else so fast. I blocked her. She showed up at my house the next day, with her baby, for the first time again. I hadn't seen her in months, and the baby said she missed me. She told me she is deeply troubled by me being so fast to leave, and turn my back on her little girl-and reflects a lot about my character.

I just don't know how to approach this or what to do. I know I'm only giving one side of the story. But this is my viewpoint either way. I question:

1-is 8 months really too long to show i have it in me to be a father figure? Is it wrong of her to expect that of me so fast?
2-am i wrong for holding resentment against her mother?
3-Should I be staying with her-or does this sound toxic?
4- I stay because its amazing to feel so loved by someone who refuses to let go or let me leave them because they are so dedicated to me. Is there more she is showing, thats bad, which I'm not seeing?