Stability for mind. Kindly help me!

I have been very strong since 4 years post break up and now my ex started talking casually and I wanted to show it did not effect and I did speak and now he has slowly over 2yrs pulled me back into his zone and daily I'm being mentally and psychologically disturbed with his thoughts and asking me to marry him ( not d right thing for me) and daily pulling me into weird moods and forcing me ... I'm not liking it at all but it's happening daily ... I'm just unable to get control over things and stay strong like I used to. This desire he is creating in me isn't enough for me to completely trust him but he isn't understanding it and mentally controlling me for his desires I'm just not done like this.. I have decided not to go back and look Wat I did. I want thinks back in my control KINDLY HELP ME