Hi i understand your predicament. If I was you, I would weigh the pros and cons how much sacrifice i am willing to give by staying in a country that i am not familiar with. How much do I know about this man, what sacrifice he is willing to give. Based on your mail, you only been there 3 weeks and the way he treated you is like a maid rather than a wife. (Personnel view). Let's say, you sacrifice to stay with Him. Are you able to take the pressure that he calling his ex to discuss about their son activities.
If you still love him, try to date him out to discuss how your feel.
I personally feel that as a couple to be unite as one flesh already not easy. Either you pressed on or return to Singapore when you are more comfortable with.