There are valid fears and all long term couples have had these exact feelings. I think the only thing you both can do is just wait and see, which sucks but it’s the only thing to do. Maybe have a time line for these things is it’s less overwhelming? Like move in before you both move to a new town, maybe at a year you can talk about mining in together and instead of a year lease just do 6 months as a way to have an outlet. Maybe after a year of living together you decide to both move. Maybe after __ years you decide to ____. Maybe that could be a way for him to see these big things have no rush and if things do end, you both have a less painful way to leave? Sounds bad I know, but maybe that’s something you both might like better that way in something happens you won’t have to worry about owing 5 months rent but only owe 1 month if you change your mind. It’s great you’re both talking about this and I don’t think he’s doubting YOU, it’s more that real life and the “big decisions” are scary and you don’t know if it’s right until you do it. It’s a valid fear and normal for everyone. My bf and I are the same ages you two are and when we had these conversations I was terrified. It helped me to do the smaller stuff to eventually lead to the bigger. My biggest fear was living together so to help prepare us both to go through with it I would stay a few days at his place or vice versa so we could develop our routines and make sure living together felt right. After a few months of that (6 or so?) we felt like moving in wouldn’t be a big change and it was a smooth transition. Now after two years of loving together we aren’t as scared to one day get married. It doesn’t feel scary because we already live together and marriage technically won’t be that different. It help to do “practice” stuff to feel less stressed. Maybe you both should come up with “practice” things to do