Senior in Highschool. BF and I are already planning our future.

So I’ve been with this lovely guy of mine for about eight months and I’m completely in love with him. I’ve fallen extremely hard, and it has been the best and we graduate in less than two months. We are already planning on living together, having kids and talking about marriage. (Not exactly in that order but anyways) is that crazy to start planning a whole life with someone that I haven’t been with for a whole year or more? 😶