Need help to stop obsessing about the future

Hi,

So my BF and I have been going out for a year and 1 month but we dated for 3/4 months before putting a title on it. We are both 21, We said our I love yous at 5 month mark, and I said it first (but I knew he felt the same, a mutual friend told me). We have been moving slowly, and are very happy. He sleeps at my house 2/3 nights a week - he still lives at home and I don't, and we usually spend Saturday/night together. Also, he works full-time as an apprentice while I'm studying.

Anyway, this last month or so I've become obsessed with thinking about the future, marriage and moving in together. I know we are young and I don't want to be married yet or for a while, but I keep thinking about will it happen, when will it happen, and I've talked to him about it and he says he doesn't ever want to get married (that's normal for most young guys?) and I'll joke around saying I'll have to find someone else to marry me, and he will agree. Yet he says he wants to be with me for a long Long time and we are serious.
Should I just take a chill pill, and let things happen? is anyone out there the same as me?