AIO because i found my girlfriend locking herself in a closet to talk to her ex husband?

Me and my girlfriend have been together for a little over 2 years now and have a brand new 4 month baby. A little over a year ago I found that she had been having conversations with her ex husband daily that would last roughly an hour long. After I found this out and began to grow a little suspicious she decided to delete everything on her phone. Her texts between the two of them, her search history, her call logs, even as far as deleting her entire amazon account. She assured me this was nothing to worry about and so I trusted her. A little while later we had an argument and I had to leave for work around 3am, I then saw on the ring camera that she had another guy come over shortly after I left that she called a "friend" and was there to just comfort her due to our argument. After he left around 6am I got a text at work that said we shouldn't see each other anymore.

Fast forward to now and I recently purchased a beautiful 3,500 sq foot home on 3 acres to give her and her 3 children a better life and a comfortable place to live. It is entirely in my name and I only charge her 500 dollars a month toward the almost 3000.00 dollar mortgage even though she makes almost as much as me due to her child support payments from her ex husband. She has 40,000 dollars in credit card debt from her previous marriage and that is why I am trying to help her out in any way I can. She only works part time and I dont mind this as I want to allow her to spend as much time with our baby as possible.

Recently she snuck onto my phone in the middle of the night while I was sleeping and woke me up to scream at me about some nude photo from 4 years ago while I was single that I had no idea was on there and a text conversation from me and my ex wife about me picking up popsicles from my work for my 2 daughters. She thought this was flirting, however I think this is just projection. She told me that she should of never had our newborn baby with me. I have been nothing but faithful and loyal and committed to her and have put up with her lies and deceptions because I love her.

Now I find that she is back to sneaking into closets to talk to her ex husband on the phone, and telling me im being insecure because it upsets me. She is leaving me with all the kids and baby to go stay the night at "friends" houses for the night. She is turning off her location. Unfortunately we work together as well and she is now gossiping to co workers about how awful I am because I won't let her keep a cat from her previous marriage anymore because it is peeing all over my house. She used to help with groceries and cooking dinner and chores but now I find myself cooking and grocery shopping and taking care of the house because she says she is tired from work so she sleeps most of the day. I dont know how much longer I can be with someone like this and the toxic environment she is creating. Is there any saving this? I want to for our daughters sake and to keep giving all the kids a great life but it is taking its toll on me mentally and honestly physically at this point. Any advice would be greatly appreciated.