What do you mean "possibly Hashimoto's"--have you been diagnosed? And why do you have to 'wait a month' if you're having symptoms? I get checked every 4 months, but if I'm having symptoms and phone my endo, he orders the blood tests immediately. You can have radical changes in your thyroid hormone levels at any time, especially if you have Hashimoto's (as I do), and it can be unrelated to any lifestyle issues. Hashimoto's is an autoimmune disease, and the antibodies can attack the gland at any time. All your symptoms could be from changes in your T3, the hormone that regulates many body functions.
Insofar as food affecting your thyroid, that would only be true if you were eating a boatload of unfermented soy poducts along with a regular diet of raw broccoli, cabbage, and spinach. Those veggies should be cooked if you're hypo, and you should be avoiding soy.
If I were you, I'd be getting my T4 and T3 levels checked ASAP.