I’m so sorry to hear about your situation. Being in a marriage with someone who cheats is very hard. There are a couple of issues I want to discuss:
Firstly, staying in a marriage with someone who is cheating on you and is not willing to stop is not something you should do if you can help it at all. By continuing to be in this relationship while he openly cheats, it is saying to him that there are no real consequences for his infidelity.
Even though you are married, I would create some space. This means, shifting your focus from his infidelity to things that make you happy regardless of his actions. Spend more time doing those things. I know this can be difficult if the relationship is rocky, but this may be as simple as getting out and taking a walk.
There needs to be a really serious conversation that goes on with this behavior. If he is cheating, at the very least, you should not be having sex with him also, because that puts you at risk for certain diseases if he isn’t using protection.
Also, if he refuses to stop, a physical separation may be necessary. But if you tell him that you are going to leave if he cheats again, you have to be prepared to leave. Otherwise he will not take you seriously and will cheat again.
I also want you to take some time and read this article about marital cheating, it should offer some guidance in what to do next:
I know you will get through this,