How do YOU heal?

When a partner cheats everyone’s first reaction is to leave (mine included, before this) but I tried to leave and I just kept coming back. It hurts so much that it physically hurts, I’m so sad and depressed.

So how do you get past that, instead of running back to someone who doesn’t deserve you? Nothing’s changed, it’s like he never cheated and went back to treated me like I’m a bother.

So how do I leave without immediately regretting it and running back? I’m not strong enough