cheated on me :(

So sorry to hear about this! I've been through a similar thing myself. What I've learnt is to get it off your chest as soon as possible as confront him about it. Keeping it in and waiting for him to tell you, from my experience, just makes things worse as you keep rethinking the scenario in your head. My advice, wait for an opportunity where it's just the two of you, without the kids around, perhaps one night in bed. Be calm about it, just tell him how you feel and judge his reaction. All the best with this, I know it can be very hard.