Fear of commitment.

Me thinks you should stop ALL talks and thoughts of marriage. Marriage wasn't your idea, someone else decided its time for you to take the next step, so obviously after a very short 9 months you are nowhere near ready if it had to be pointed out to you.

You shouldn't marry someone because its the next logical step, you shouldn't marry someone because she's perfect for you and you're scared she may run off.

You marry them because you want to, and you're ready to. If she's the right woman, she's not going anywhere.

I suggest you address the topic of marriage when its actually your idea.