Am I the problem or am I being taken for Granted

TL;DR:
I’m a 31M in a 1+ year relationship with a 28F who lied about being separated from her husband. She moved in, kept flirting with other men, and demanded I pay for everything while showing no empathy or affection. I sacrificed a lot financially and emotionally, but she still criticizes me and won’t give reassurance. My family cut ties with me over this, and I’m emotionally drained. I’m torn between leaving to rebuild my life or staying stuck. Am I the problem, or am I being used? I need honest advice

Full Context:
I’m 31M, my girlfriend is 28F. We’ve been together for about a year and three months. Things started great — deep convos, fun dates, genuine connection. But early on, I noticed I couldn’t call her at night, and she never let me visit her place. Eventually, she admitted she was still living with her husband, though she claimed they were separated and divorcing after she had cheated on him.

I was shocked but gave her the benefit of the doubt. A month in, she said she needed a place to stay, so I let her move in. That’s when things really started to shift. She kept in contact with the guy she cheated with, and many other men messaged her. When I raised concerns, she told me, “I’m attractive, I’ll get attention.” I asked her to be respectful and let people know she was in a relationship.

Later, she gave her number to a guy from church (after denying it at first), flirted with him over texts, and sent him selfies — some taken while lying next to me. I also found she was texting her ex, the same guy she cheated with. I was heartbroken. She begged me to stay, gave me her phone password, and promised to cut them off. Things got better… temporarily.

Eventually, she told me I needed to pay for everything — rent, groceries, luxury items — even though I was already struggling financially and paying down a credit card she helped me get. She constantly compared me to other men who “would give her more,” and said she couldn’t love me until I paid off the debt and spoiled her.

Despite all of that, I sacrificed so much for her — skipped meals, gave up haircuts, worked multiple jobs — just to make her happy. But nothing is ever enough. She doesn’t show empathy, shuts down when I express my feelings, and avoids giving affection or reassurance. She even once hit me while drunk after I picked her up from a party for her own safety.

My family recently cut ties with me because of this relationship. I had to surrender my dog. I feel emotionally drained and like I’ve completely lost myself.

She still tells me that I don’t make her grow, when all I’ve done is try to love her, support her, and help her evolve. She claims she wants a lavish lifestyle, and I just can’t afford to keep up.

I know this relationship isn’t healthy, but I’ve invested so much. I’m stuck between leaving and rebuilding my life or staying and constantly feeling like I’ll never be enough.

Am I really the one messing this up? Or am I being manipulated and used? I need an honest outside perspective.