It could be a tight muscle, hard to say, but hopefully can post an image of the muscles in the area, might help you identify which one could be causing problems:
There have been a few discussions recently about tight muscles & the pain that they can cause, as nerves can get trapped & cause pain. Pain & tension in the masseter muscle & sternocleidomastoid muscle specifically have been mentioned, & suggestions for help. Here’s a couple of links:
If you search with these muscle names it’ll come up with more!
Hope this helps; it’s very early days since your surgery, so unlikely to be anything permanent. If it’s not too painful & your scar has healed, it’s probably okay to gently massage the area with oil.
