Getting sooool angry

I'm sooo pissed of so a few weeks back I found out my partner cheated on me! We spoke and I agreed to try and give it another go I told him I don't trust him and he said he will prove to me! We have three children so in a way I want to make it work! He had already took himself of Facebook that was down to him witch I was kind of happy about, then tonight we are sitting on the sofa and he picks up he's iPad and I see he had been on Facebook!!! When I said are you back on Facebook he got all posed off started calling me a fool and telling me to stop watching he's every move!!! I don't know what to do any more