That's great that you were able to talk to your T about how you are feeling and that you gave her the knife. And good that's she's giving you biweekly sessions. Does she allow between-session contact? That could help you now too.

Do you know if your headaches are definitely migraines rather than tension headaches? Treatment could be different depending. I have both types, and find that tension is more in my neck/back of my head, while migraines are throbbing on one side. Plus I get visual auras before migraines (not everyone does), with flashing lights in one of my eyes and sometimes numbness (I get them much less frequently now that I'm no longer on hormonal birth control). Exercises to stretch and relax your neck can help with both kinds though--just try searching for "neck exercises" or something like that. There are also some trigger points in the back of your neck that can help relieve/prevent headaches if you massage them regularly--I got a book on Amazon about them.