Coordinator not responding?!

What vendors are you talking about? DJ? Photographer? Those should be booked before January because you want to meet with them and see if you'll even like those vendors or want to search for your own...you want to know how much they charge, what their packages are, deposits, etc. You def want to reach out to them now and start to schedule meetings before you get busy with classes.

Call and ask to speak to her supervisor. Tell them what has been going on and insist on being moved to another coordinator.

What exactly is her job? Is she a full out wedding planner? Or just a coordinator the month/day of? Do you book the vendors yourself? Or does she have to do it?

I'd be pretty stressed out then. Do their vendors work for other venues? If so, I'd be worried they are already booked (at least the good ones). If they work for only then, it's less stressful because they obviously won't be busy. I'd just send another email explaining your stress and discomfort with the planning experience so far, and let her know specific things you want booked in the next month or so. If she doesn't answer, I'd call the venue and give them the same message.

I think you need to relax. You have months until your wedding. It depends on when you actually need to decide everything. If you just need to talk to her to decide on menu itself (the caterer is either the venue or already chosen), then wait until January or March. The menu might change for the spring season, and you only need to put "chicken, fish, etc" on the response cards. If its a buffet menu, then you have plenty of time. My coordinator did not respond very well in the months leading up to my wedding, but the month before hand, she was fabulous. Honestly, the coordinator is not focused on your wedding, he/she is worried about everyone getting married this weekend. When it's your turn, she'll be there.