When your partner lies and betrays you it hurts and puts a spanner in the works. He should be ashamed and remorseful. If he is genuinely sorry about lying to you and betraying your trust and works hard to rebuild the trust in the relationship I'd think he's learnt from what he has done and you could start over.
But, he doesn't sound like he is even sorry or thinks he has done anything wrong. I would also be questioning his loyalty.
I think he needs to really understand how this has effected you and made you question everything.
If he is genuinely sorry and remorseful you have something to work with but if he isn't whose to say he hasn't done this before, or will do this again.
A relationship councillor could help.
I wish U all the best.