Make sure she understands how important this is to you, and then probably give her some time. This is probably completely new territory for her, and she probably didn’t expect you to reveal a suppressed side if yourself after multiple years of marriage.

However I do believe it is very important you are with her while she is considering this, who knows what kind of thoughts she is having, and not being able to ask you questions on what exactly it is you want, will probably lead her imagination to go wild. If she is as vanilla as your first comment implied, she might not be keen on giving you a chance if what she thinks you asked of her was the more extreme forms of domination. In my ears at least, 3 days without talking after something this important is way too long. A single day at maximum to calm down, and then you need to talk it out and make sure you are actually understanding what you are talking about, and not just talking over each other. Communication is so important yet so hard to get right.

Good luck to both of you and my heart goes out to you.