At least you got some meds to help you through. It may take awhile to get an MRI, keep pushing. After the MRI you will need an EMG so set up an appointment with a Neurologist
now. Just tell them that you are paying cash but make one with a doctor that is covered by your insurance. That way, when you go in, you can use your insurance but will get an appointment right away. Push for lots of tests, which ever ones that your insurance will cover.
The last word that you want is surgery so explore all of your options.
Next time, tell them that your whole, entire arm is numb.
There has to be something serious going on or your fingers would not be numb.
Meantime, make an appointment with whoever you can so that you can get some sort of meds to take down the inflammation. At least they didn't send you for a cortizone shot. Don't do that unless they force you to and then ask for any information that they can give you and then look at them and tell them that you read that it causes tissue damage, they make back pedal on it if you are informed.
Your first concern is to get the inflammation down. If it is the nerve in your neck, don't raise your arm over your shoulder, and don't tilt your head to your neck or back, especially in the shower when washing your hair. That traps the nerve.
Your next concern is to set up appointments. This is a biggie as it takes a lot of pushing to get one in the next month. They are all booked up. There will be a lot of hoops and hurdles. Familiarize yourself with what it takes to move through the system quickly.
Pain meds are great, but they also dull the pain and you end up doing things that normally send pain signals to the brain. Pain is an indicator that something is wrong. Keep in touch with your pain and your pain level.