Financial talk

i have been with this woman for three years, i've not asked her to marry me, though i had been wanting to for quite some time.. we have both been married once before and i didn't want it to be a b/s halfway put together deal.. ii wanted to give her an awesome wedding, and have time under our belt to make sure for both of us. we have financial problems, i have a daughter whom is 9, i am 30 and she's 22. i had been picking up my daughter every other weekend for a couple of years, my girlfriend has made several of those trips alone as i was at work, she made the effort to get my daughter for me (keep in mind it's a 10 hr drive roundtrip). for the last 6 months of school my daughter has been living with us, it's been difficult for all of us, she changed her work schedule to suit picking up my daughter from school, as well as dropping her off in the mornings. between work, my daughter, and the band i'm in i stay pretty busy, we only have one car right now and work 45 min in opposite directions(our routine during school was this wake up take me to work 30 min, take daughter to school 30 min, go to work 35 min, work from 9-2, go pick up daughter from school 35, go home and start homework @3, at 5 go pick me up 30 min, and finally came home for the night) she's told me at times that we should get away for the weekend and things of that nature, the band takes up most saturdays, and like i said money is tight anyways. she's told me that she doesn't feel like my daughter respects her, i also keep an open friendship(being able to talk and laugh w/ my exwife)for the sake of our daughter. this summer my daughter went to spend the summer with her mom, we've had the house to ourselves again and have kind of not known what to do with ourselves somewhat, have both started drinking heavier than normal and spend most nights starring at the TV. ** about a month ago i was on the phone with my daughter and she told me that she wanted me and momma to get back together, i asked her to give the phone to her mom and stepped outside to talk about, i felt with past issues that i didn't want her to have to hear about this. i was told that what i did was completely out of line by my girlfriend. about 3 weeks ago i felt that something wasn't quite right, that gut feeling, i asked my girlfriend if there was anything she wanted to talk about, nope. i told her that i felt that someone was taking up her time, i said i don't if it's a man or a woman, that i wasn't thinking she was sleeping around on me or anything but somethings up, she said there was nothing. 2 weeks ago i confronted her and said i wouldn't blow up or whatever, but, just tell me, she told me that she had met a guy at work but they were just friends,nothing outside of work, and that was all that there was. oh, i blew up somewhat also afterwards. not feeling like that was all of it, i dug a little and found the guys phine number, so i called him and asked him how much of friends they were, he said nothing outside of work, i told him of a phone she made to him as soon as she got off a few weeks ago, he then blew up and started calling me an f*ing f*gg*t and told not to call his f*ing phone again. since then i told her as long as they didn't sleep together i'd be willing to try and make it work. she went back to work and cut ties with him like i asked and told me about it, told him that she wasn't going to leave me, his answer was that he figured that much. that she didn't need to talk to him and he needed to avoid her. i am at a crossroads and feel betrayed, but i don't want to lose her.. while fighting before she told me anything she packed some stuff and was going to leave without saying anything, she's had friends at work that she talks about guys and girls alike, she never talked of this one. everytime i confronted her she said that was all of it, and then i find more. why did she hide it and why did he cuss me out. i feel like he had other intentions and she was enjoying the feeling of being pursued and it got a little out of hand maybe emotional, maybe a possibility of sex idunno. maybe she's questioning my commitment or lack of, thinking maybe she's just my nanny or whatever? should i be worried about the possibility of it happening again (given i will pay more attention to her) if things get stale is she going to do this everytime we hit a stale moment, should i worry about her having sex with this man? i have a daughter that depends on me and i don't need to catch anything or whatever. she is very upset whether faking it or not there have been a many of tears on both ends. says she wants to make it work and it will never happen again, feels like a crappy person, and said she was wrong. what do you guys think???