What do I do?

My girlfriend recently broke up with me, and I helped her out even after we broke up. Mostly because I knew she was still going to need help, and she has no one else to help her out. She needed help letting her dogs out and told me she was heading out of town for Christmas shopping and stayed out until 4:00 am. Turns out she was going to have sex with another guy, and had been having sex with another guy since the weekend we broke up. Turns out she had been using me so she can have sex and didn’t even bother to tell me the truth until the guy ghosted her. Then when I was frustrated about it I was the bad guy.

I found this out last night. I didn’t message her at all today, but just a few hours ago she sends me snaps and I’ve been afraid to check them. Do I check them or do I ignore them?