Sounds like you are in a tough spot. I found myself in a similar situation with my H a few years ago. Like you I. Met him online and from the beginning I was under the impression that the relationship would lead to a family and marriage. 2 years in I started to try to talk about the idea of getting married he would always change the subject or just turn it into a joke. I figured he wasn't ready and waited another year before I pushes the issue again. He responded by telling me that he just didn't think he wanted to get married. I wanted to have a dialoge about the reasons why but he wouldn't say. He continued to flip flop with yeah someday or maybes or its not you I just don't want to marry anyone. Well like you marriage and family were two things that I knew I needed in my life. I began to get depressed and frustrated. After a few months I faced the reality that if after 3 years he didn't want to marry me then he probably never would. I was afraid of getting pregnant and having him be with me out of obligation.
It was the hardest thing I have ever done but I came to the conclusion that the best thing for both of us was for me to end the relationship. I told him that I loved him deeply and was had been hoping to make a life with him. That I had been wanting to marry him but he hadn't seemed intersted so I was going to go find someone that was. I politley moved out and wished him a happy life. I truly believed that would be the end of us and I was okay if that was the case.
After thinking it over H decided that his life was much better with me than without me. And obviously we got married. I'm not saying that this is the right thing for your relationship or that if you do leave he will agree to marry you. The moral of my story is to never sacrifce your dreams to fear especially someone elses fear. Good luck with everything keep posting
Everything comes from within