Yeah, that happened to my son. He was started on Levothyroxine, and one week later he collapsed on the kitchen floor - passed out, just a few seconds. Had severe dizziness, nausea and tachycardia after. Turned out he had adrenal insufficiency, so he was immediately started on a full replacement dose of hydrocortisone, which unfortunately, only made him feel worse, for a very long time. (He has a pituitary tumor)
Thyroxine effects your cortisol level, so while you are getting your thyroid hormones retested, have morning cortisol tested too.
Need to check with pharmacy what they actually gave you. Maybe something wrong with the prescription or the batch of meds.
Then need thyroid testing - TSH, FT3, FT4.
What you describe doesn't sound like a typical reaction to thyroid meds. Something else happening.
The only way to know if it was pituitary source would be testing - low TSH, or other tests.
Losing vision, but on the sides, is a sign, but not what you are describing.