Could you please let me know how this situation worked out. I am worried about your safety, what the other users said is correct, he could be very dangerous.
Did you tell your parents??
How old are you?
Do you feel safe, like the situation is handled now?
Please write back as soon as you can, I am very worried about you.
As a side-note, even if you are over 18 what he is doing is at LEAST a misdemeanor, and you could call the police, press charges and have him arrested. He is showing signs of true perversion, sometimes sending a message like pressing charges, would be enough to tell him that he can't take advantage of you.
Also, telling your aunt is not the best idea, at least not before you have other people on your side. It is VERY likely that she will not believe you, women who marry men like that like to live in denial. You need people to support you not try and convince you that he doesn't mean any harm.