It might be helpful to think of specific behaviours he could do that would make you feel more irreplaceable and loved and cherished. Our feelings are important and they get us all worked up and sometimes it can be hard to get specific. But if all you can name is 'I feel ______about this,' that can be hard him to DO anything about.
But if you said, 'maybe sometimes you could bring me flowers, or surprise me with home-cooked meal' (or whatever makes you happy) then he would have actions to take and you would have 'evidence' (for lack of a better word) of his feelings.
Folks around here recommend the five love languages a lot. I went and took the online test, (even though I thought I knew all that stuff about myself already) and I found it helpful. It really explained why I have the two boyfriends I do. I had a super high score on two of the languages and very low on the other three. One bf is big on one, the other on the other language.
Also, to give you a sense of time perspective. I've known both of my boyfriends for EIGHT YEARS. Eight years before we even considered poly. I'm not saying that everyone should take that long; but I am saying that 2-3 months is not very much at all.
So, maybe you could also do some behaviours that will increase your self-esteem (because you're the only one who can do something about that).
wishing you both the best!
Love is that condition in which the happiness of another person is essential to your own...
Robert A. Heinlein
Me: female, bi, (formerly hinge of a vee)
with FirstBoyFriend (FBF)(moderately long-distance)
and no longer with CurrentBoyFriend (CBF)(who now lives in a house far away-with stairs I can't climb)