Advice for leaving a cheating drug using baby daddy

I feel like I need advice .

I’ve been with my boyfriend for the last 5 years .

I was a different person when I started this relationship. I had no self respect no morals no goals . We partied , we fought , we disrespected each other . 3 years ago I got sober . I feel like my entire look on life in one day just changed . It was like a switch and I grew up. And thankfully I did . 1 year ago I had my daughter . I feel like a great mom , I feel like it’s the only thing I’m meant to do .

However, my boyfriend has been on and off with his sobriety. Sometimes he goes six months then a relapse then 6 more months . But he started in the beginning of December and so far had 3 benders since .

I’ve found out about him cheating & messaging other girls , too many times to count .

When I had no self worth I stayed and stayed and stayed . Anyway , today I found out about him messaging another girl on the last bender .

I don’t want to be with him anymore . He says he was only talking to her about stuff that he goes through (ptsd from things he’s seen as a firefighter) hes a liar and she has messaged her friend about thinking about sleeping with him so I know it was more than that .

Anyway , I grew up being raised for the most part by a single father . I love my mom don’t get me wrong but I don’t think her priorities were in check when I was young . So I always knew when I have children I want to do EVERYTHING I possibly can to be there for her every single day and to give her a real family . And do EVERYTHING I can to keep that family intact .

My boyfriend says he’s never gonna do drugs or message girls again but he’s said it before . I know he doesn’t want to but I know 99.99% he will .

The thought of leaving and have to give up time with my daughter makes me sick to my stomach .

I don’t have what I need financially to leave this minute . I do however make pretty good money with my new job so it won’t take long .

And I bought ya a trip for 6000 down south in May that I could refund . But I kind of feel like just taking someone else . Since I’m looking forward to that experience with my daughter .

I guess I’m just looking for advice and stories on how other people may have left ? What rights do I have to my daughter? How much do I have to give up? I’m in Canada .

Thank you .