Leave him. Don't waste your time with someone who doesn't want to get married. You want to get married but he is okay with the idea of not get married. It would have been okay if he had said that you wait for a period of time. By saying marriage won't work out between the two of you, he is saying that he isn't committed to the relationship.
A partner being possessive of another partner isn't a good sign of a healthy relationship. Again, he is going out with your friends and doesn't respond to your texts.
Your boyfriend lacks respect. He doesn't respect you or your relationship. I can't believe his assertion that he loves you. If he loves you, he can't behave in that manner.
It's time to call the shots - end the relationship. I wouldn't advise you to continue with the relationship Ben if he pleads for another chance or for the relationship to continue.
He is using you. That is not love.