Ditto urgent care, but I'd like to add that almost the exact same thing happened to me a few months ago. (I was in bed, I turned my head to look at the clock, cracking noise, instant pain, couldn't move head). I spent the day moving as little as possible and the pain eased away after a few hours, I was fine the next day.
My DH has experience throwing his back out from time to time. He said that all I did was throw my back out, only it was my upper back instead of lower. All they can do when that happens is tell you to rest and take pain reliever.
So, definitely get it checked out, but you may be fine in a few hours.
To follow on Oreos, I've thrown my lower back out and man... it SUCKS. Pain, can't move, etc. If that's all this is - yes, it's largely "time" that you need.
But - I just wouldn't take a chance w/ neck/spinal stuff. Even if it's simple, they might be able to give you some strong meds to help w/ the pain.
Please go in. Not to sound alarming, but I ignored back pain for a couple of months (yes, I was an idiot) and suddenly got to the point I could hardly walk and needed surgery to fix it.
Go, before it gets worse, and they can help with the severe pain.
You say you heard something crack. Serious injuries do sometimes happen from the most mundane of issues. I'm really not trying to be alarmist, but it's the cracking part that concerns me.
I am not going to sit in outpatients (I'm assuming this is the Canadian equivalent to your urgent care) for hours on Halloween for a sore neck.
I was there for 8 hours when I was having a miscarriage. I will be there for 20 with a sore neck. No.
Other alternatives. Honey? A poultice? Alcohol? Keep it coming.
Oh, that 8 hour wait sucks. US Urgent Care is often privately owned for profit type place. They just do simple stuff. So the wait is generally under an hour.
I would take Motrin and try to stretch. I mean assuming you can walk and stuff you probably just pulled a muscle.
I cracked two ribs from sneezing once so I understand your frustration about the cause but the popping sound in the neck is somewhat worrisome to me.
If you do not want to sit and wait, which I get, ice the shot out of it and ibuprofen up. Maybe see if you can get into a chiro too. They may be able to help.