Did they do a nerve block??? I ask because it was my understanding that with trigger points the needle is very small and is more of a surface shot.
I personally had a problem with a nerve block that caused very intense pain and sounds similiar to what you are going thru.
When you have an injection, I have been told, that sometimes the needle can come to close to the mylein sheath and it can cause SEVERE pain and it can take months/years to heal.

I pray this is not your case. If this happened you will probably need stronger pain meds and you will be on them for sometime until the nerve calms down.
I pray that this is not your case. If you have any questions, I will be glad to answer them.