Am I overreacting My girl was flirting with a coworker I found messages proving it and message dude that she was with me her boyfriend this was her reply

I don’t think I am but I am going insane and I have no idea what to do our lives are completely wrapped in each other and she literally depends on me not to be homeless so I feel like I can’t leave. She says she just flirts because it’s fun and that she turns him down before anything and I just need someone to talk about all this bullshit.