Needing advice from blended families

Hi everyone. Moms with blended families, maybe you can help! I’m with my boyfriend, he has a daughter, and I have my two girls. Our girls are young. I have a few things wrong with this… His child’s mom and I get along very well. She’s told me in the past he asked for her back, and he admitted it but said it was at the start of our relationship, so it didn’t matter. He will buy her coffee in the morning even though she didn’t ask. He and his mom drive her around for the kid’s appointment and such. His mother never asks me how I am, she’s constantly texting his kid’s mom and her family, and even she thinks it’s weird. This has been ongoing. He’s lied to me about going places with her like shopping and such; at the beginning of our relationship… he got really drunk and ignored me all day and hung with her. We’re now three years in this, and I’m not over it. It feels like he’s doing nothing to provide us a house. I’m working full time, too, and it’s like he just wants to live with his mom. He will constantly be at his mom’s. His father also told his kid’s grandmom on her mom’s side I was nice, but I come with baggage (my kids). He will complain about driving my girls to school in the morning; he is fed a hot meal every night by me. I clean and cook and work. There’s so much. His mom told me once it would be easier off the kid had her mom and dad just in the picture without me. Our kids constantly fight. All five of us share a room. I’m so sick of it. However, I feel like staying together is easier. He’s constantly arguing with me about dumb stuff like how my kids should be raised religiously or whatever. I’m scared of heartbreak. It’ll kill me to see him with someone else, and to be honest, I feel like we sometimes stay just for the sex. I just needed to vent, but everyone’s mad at me for taking him back constantly. My kids do love him, but I don’t feel like they are treated fairly because I feel like his child is praised a lot more. Is this something you work through, or should I have left when he asked for his ex back? She did say no at the time he asked. He tried to say he didn’t ask for her back; he asked her what she thought about if they were together again, which is the same thing, in my opinion.