I'm sorry you're here, and I'm doubly sorry to have to be the one to say this, but:
Go home.
If he has so little respect for you that he is willing to cheat on you and your daughter, knowing you have no support network, then he doesn't deserve to have you.
You aren't going to change him, and things aren't going to magically get better once you're married. If anything, they will get worse.
Pack your things, take your daughter back home, and find someone who loves you and treats the two of you like you deserve to be treated.
Your daughter needs someone to show her she deserves to be treated with respect and love.
She needs someone to show her that it's better to be alone than stuck with someone who treats you badly.
