You need to decide what's more important to you, getting married or being with him.
For example, I want to get married so I can spend the rest of my life with the man of my dreams. I think I've met that man now, but like your boyfriend he doesn't want to ever get married. So for me, spending the rest of my life with him is more important than having a ring on my finger. If it means I never get married, then so be it. I'll be disappointed of course, but being with him is what matters most to me.
But if being married is something that you feel you absolutely need before you can have kids and start a family then you two need to make a decision together about either getting married or parting ways.
It is. This is a big decision, it's something that is going to effect the rest of your life so if you guys want different things, and neither one of you is willing to compromise, then it's probably better to move on and find someone who wants the same thing you want.
I would try talking to him about it. Tell him that you want marriage and won't have kids unless your married. Don't try and force him to marry you or anything just let him know how you feel. But if he is serious about never wanting to get married, then there is no real point in continuing the relationship.