What is my boyfriend thinking about our relationship?

My boyfriend (22, almost 23) has told me before that he will ask me to marry him on our 2 year anniversary. He also wants to get married about 6 months later. This was fine with me when he brought it up 6 or 7 months ago, but now that I have thought about it, it annoys me. Why? Because 1) I want time to plan a wedding, and I can’t do that in 6 months. I don’t think he understands. 2) He already acts like we’re engaged or married, and so does his family and most of mine. We are together constantly. We go on vacations together already, go to all of our family things together (show up together like all the married couples do, not with our parents). His mother took a family picture of us, and I didn’t know it, but it went on her Christmas card. It has their last name on it, and I am the only person in that picture that isn’t part of the family. It’s his parents, him, his brother and his wife and kids, and his other brother, and me. Nobody acted like this was weird at all. At a Christmas thing the other day, a woman that lived next door to his grandma asked about me and if I was his wife. His aunt was like, no, but we’re expecting it soon!

It just annoys me, too, that he acts like we have a superior relationship to others, and has our future all planned out. I wish he would ask me, because I want to get married then too. I want time to plan the wedding and I want to stop feeling like an idiot when people ask when the wedding is. All our friends are engaged and didn’t start acting the way we do until they GOT engaged. It’s weird and I just want to know:

Why is he acting so serious? Does he think it’s okay to be this serious/treat our relationship like this without MAKING it official?? Thanks!! Any input or advice on any part of this will be appreciated.