Cancer doesn't happen that fast so don't worry about that. You should look into both migraines and TMJ. Definitely get it checked. You don't need to go through this pain.
No it can not be a brain tumor then. Not if you were cleared a few months ago.
But headache can still be disturbing, so you should anyway reach out to your doctor to see if you can maybe get some help. And if you have not had your headaches diagnosed before it is also a good idea for that reason.
Good luck and take care!
Hi and welcome to the Migraines & Headaches Community.
I am no doctor but I highly doubt that even if you did have a brain tumor pop up since Nov that it would be large enough to cause problems. BUT YOU SHOULD GET CHECKED!!
That being said, it could just be migraines which are bothersome but not dangerous. I have posted on many many different threads about tips you can try to help migraines. Take a look and maybe some of them will help until you get to see your doctor.