Ummmmmmmm, you were used, duped and betrayed. And I think this man will continue to do so as long as you allow it. Remember, it's not only you but your 2 daughters who will also be affected by this situation. Giving him 6 weeks to get out is not mean; I think it's quite generous. If you don't end it sometime, you can be sure he won't. Why would he? He's got a place to stay and someone to help with his child.
I say get out....the sooner the better. Staying in will only cost you more in the long run......more stress, more unhappiness, and possibly more $$. Stop allowing yourself to be lied to and manipulated by him.