Advice please!!

Oh boy where do I start? So my boyfriend and I have been together for 2.5 years he has a 3 year old with someone else and we have a 6 month old son together. So the last 4 months and ever since we have moved into our new place have been hell. We fight constantly because he does suspicions stuff like stay up late at night, “walk around the neighborhood”, stay in the bathroom until 4am, hiding his phone,etc. We also have missed 3 payments on our place and had to have my mom bail us out each time. Come to find out he was spending the money on cocaine and leaving those times when he said he was just “walking around”. While I’m at home with both of the kids because we have his daughter 50/50. Ohh and he has a hair follicle test (drug test that goes back 90 days) for his daughters family court on May 1st. He also one of those nights kissed another girl. I could tell something was up because cmon I’ve been with him for this long I know how he acts. I just don’t even know what to do anymore. I’m so hurt betrayed and we are still constantly fighting. He says he’s going to change and wants to change. But I’m at my wits end with it all because I know I deserve better and so do these kids. I just love him so damn much and we have a baby together so it’s really hard to leave. But I guess where I need advice is do I stay and see if he changes? Or do I leave? And if I do leave do I tell his other baby momma what’s been going on (drug wise) even though his daughter has been in my care the whole time not his.

If this is in the wrong area please remove.