I proposed and he said no, I don't know 😢

I'm bi, 30, and he's gay, 34. We've been dating for five years in a monogamous relationship.

On Saturday night, I took him to some of our favourite spots and then back home. I said soppy stuff, like, "Harvey Dent (he's a big fan of the Batman trilogy) said, 'The night is darkest just before the dawn,' and you came into my life brighter than any dawn. I didn’t even realise how dark my life was before you…"

I got down on one knee and proposed.

He replied, "No, I don't know." He said he loves me but he's worried he won't be enough for me. He mentioned that I don’t really get involved in the gay community, that I'm religious, and that when I see my friends settling down with a "natural" family, I might want that too.

I told him I didn’t know he felt that way. I reminded him that we’ve discussed the future, family, and so on, and this never came up before. I said I love that we’re different, and that I proposed because I see him as my natural family.

He said he needs time to think about it. It’s been frosty since. I know we're still together, but I’m heartbroken. I spoke to two friends about it, and they said that even if he says yes, those concerns are coming from distrust and it might not work out.

Any advice? Ideally, positive.