Something’s missing with my BF?

It’s just this feeling I have like deep down LOL. Idk what it is, but I just feel like somethings missing when I’m with him. I am very extroverted and like to be social and he’s introverted and stays at home a lot. I’ve brought this up several times, and I accept that is just his personality and what’s he’s accustomed too now that he’s getting older. We’re seven years apart and I have always dated older guys. But idk....ive been doubting our relationship a lot recently and starting to wonder if I can see myself marrying him or not. Is this normal? I feel like it’s too early to tell bc we’ve only been with each other for nine months. If it helps, I’m 24 and he is 31.