Partner scared of newborns?

I got pregnant in September and my partner freaked out. He basically asked if it was too late to take plan b so he really wasn't ready.  Well things didn't end up going well and we lost our little bean early on.

A couple months after I talked to my partner about possibly trying for our rainbow baby and he immediately shot it down. He says he wants kids one day but he's not ready yet. He says he's scared of me becoming pregnant and he's scared of being a father to a brand new baby. He told me he would be fine if they were older but he's scared of the first year of life...

I don't know what to do really. I feel like I'm stuck. I desperately want to start a family with him. How can I help him get over this fear? I obviously want him on the same page when we start our family, I don't want to pressure him and have him end up resenting me or our possible child, but I also don't want to wait another 5 years...

My mom always says that no one is really ready to be a parent until they actually become one, and even than sometimes it still can take a bit to find the swing of things.

I know I still have lots of time to have kids. We are still very young. I just turned 25 and my partner is Turing 25 in a couple weeks, so realistically we do still have time I just never imagined to be 25 and not have at least 1 child.

I just don't know how to help him get comfortable and I'm worried his fear will continue to over rule him until it's too late.

It's not like this topic just came out of the blue one day we've talked about it for years. We are high-school sweethearts. After we graduated we started to talk about having a family. At that time we agreed to wait till after he went to college. Well life took a massive twist and his brother got hit by a car, he survived thankfully but did get really injured. After the accident my partners mental health started to get bad. He got the help he needed and he got alot better. He started working full time. Couple years passed and we brought up the conversation again somehow. We agreed to wait till we were 23. Time passed and obviously by this post plans have changed again.

If your partner was having the same feelings what did you say or do to help them? How can I make him more comfortable with the thought of taking care of a newborn? From what he says he would be fine if we adopted a child over the age of 2 and obviously adoption is a wonderful thing and there so many children waiting for loving homes however I just always imagined my first child being my own and than adopting or even fostering as I came from a dysfunctional foster home and understand how "broken" some of those kids are.

Thanks for reading and thank your for the advice In advance if you give you any.