Sorry to hear that you're in pain...
How long ago did it happen?
Was it caused by recent specific activity or a gradual onset of weakness/pain and "sleepy arm"?
How much is your pain from scale 0 to 10? and where exactly is it?
Is the pain constant or intermittent depending on the activities you do?
When do you get the pain? (is it more when you wake up / during the day / in the evening-night time?)
What certain activity (other than lifting / pop-up) makes the pain worse?
What makes is relief the pain?
ccrhee wrote: My arm permanently feels like I've slept on it.
Do you mean, numb / pins and needles / altered sensation?
Is there any swelling? Hot sensation around the area? Icing (as Phil mentioned above) is a good first aid if the swelling/hotness is withon 1 - 7ish days.
Have you had anything like this before?
Worth seeing a physio (than a GP who’ll eventually refer you to physio anyways), who will ask something similar to above questions.
It'll help if you can note any of the above and try to figure out the pattern of your symptoms.
Hope this helps. Good luck!