I don't believe what happened was in any way your fault. If he loves you he will apologise in the most meaningful way to you. Don't just jump back into his arms because he says he loves you. Love is an action more than it is a feeling. Jesus died for us while we were dead in our sins and that is how we are to love. Love him and forgive him but if he can't prove he loves you and admit that it was a mistake then you might need counciling as a couple. I am not expert just my opinion, sorry for longish answer.