Good that you recognized you were looking for meaning in your relationship with him. While it is nice to think that more time together or moving in together could "mean" a more secure, long term R... there is never a guarantee.
Do you mainly stay at his place for "sleepovers" or does he sometimes go to your place?
When you stay over at his place, is that usually only on a weekend?
How long is it between times that you have sleepovers?
What I'm getting at is... is there a point where you feel he's uncomfortable with you around so much? Or that you are uncomfortable with him around, so much?
Is there a way that you might bring more... "stuff"... over to his place, as "just in case" items or to make your presence in his life a little more... persistent?
Alternately, if he comes over to your place, do you have anything of his, there?
It is possible that while he may be scared to be more permanently involved, it may be because... each time the two of you go separate ways, he may be wondering... "maybe she won't come back, again..."
Just thinking out loud, here...
Also, what really ARE his fears? Did you say he was worried that it might happen again. You mentioned something about him wondering if it might be easier to just start again with someone else?
Knowing what his REAL (deep) fears are, might be worth looking into. Sometimes we will say a fear, which could be valid, yet we're hiding something deeper... which might even be unconscious.
