Yes, I would bring it up again. He expressed his fears over a year ago and you now are with him almost all of the time. Did what he feared come true? If not, then it is time to find out if he is ready to live together.

And, at your ages, if he still isn't comfortable with doing so, then you might want to weigh your next move. Perhaps you decide to spend much, much less time with him (which will cause him to think about how much he does or doesn't want to be with you), or you break off the relationship and move on with your life. It depends upon what you eventually want - marriage and children or content to remain single, or???

There is a saying - ugly, but too true for many - "why buy the cow when you can drink the milk for free?"

So, yes, my opinion is that you should have the conversation again.