Boyfriend stopped talking about marriage (very long)

So in the beginning part of our relationship my boyfriend and I both confessed that we thought the other was "the one". He was constantly bringing up how he wanted to marry me, how he wanted me to have his last name, how he wanted a family with me. He even said he wanted to propose in "a year" which will be this August from the date he said that. Then he started telling his friends that I'm "wife material" . And shortly after that, he asked me to buy a nice formal dress so he can take me out to dinner downtown although he did say the dinner wouldn't be for "a while"

After all that, all marriage comments from him have stopped completely.

I'm not gonna lie, I did bring it up a few more times and now he's saying that we have to live together for a bit before getting engaged. Even though I wanna be engaged before moving in together.

He has been very stressed with work lately but now if I bring it up, he says that it's too early for us to get engaged. I don't believe love has a time line. Some people are happily married after dating for only 2 months! We've been together for 8 months.

I know marriage is a big, super huge, scary commitment to men but not to me. We do a lot for each other. I consider him more than a boyfriend because that label just seems a little juvenile sometimes compared to how strong my relationship actually is.

I just want to be his wife sooner than later. I don't know why I'm so obsessed with the idea of marriage. Believe me, I love my boyfriend and I don't wanna just "be married", I wanna be married to him. I want to step into the next stage in life. I've been a college student for 5 years so I'm just ready to move on if that makes sense. I wanna keep a home with him. I wanna take care of him and his kids and cook for him and everything else. Some women want to be mothers, I want to be a wife and a mother.

So my questions:

1. Why is my boyfriend not talking about marriage anymore?

2. How can I get over myself and stop caring about the next step?

Hobbies don't help. I'm in college, I dance, I knit, I exercise, I've started cooking, I read, I watch TV, I participate in college organizations. Nothing distracts me enough from the idea that I've found the man of my dreams and I want to do more and be more with him. I know a lot of people don't care for marriage but I do. I think being a wife is more important than being a girlfriend.

Please help :(

Side note: I know some people might ask our ages. I'm 22, he's 23. He's got a nice, steady job and after I graduate I will be getting into the education field so my job will be steady too.