Advice needed please!

My bf father died in September. Ever since then my boyfriend has been... I don’t know how to describe it, but like it feels like he’s rushing our relationship. He wants to move in together and get married and have a baby.

And I’m not ready for any of that at all. But I don’t know how to tell him this without hurting his feelings cause I know he is still grieving.

I’m still young, I just started my twenties and although we have been dating for a few years, I don’t want to settle down with him since he’s been my only boyfriend. Don’t get me wrong I do love him but I also want to experience more, without being tied up in marriage. I feel like if I said this to him he will become even more depressed though.

Can I get some advice please? How should I explain this to him without hurting his feelings?