Hi Robert, constant hi-pitched T for 6 months here (initially brought on by a cold that lead to a sinus infection). Had my first cold since then (started about a week ago). I spiked on the second day, and 3 days later j returned to baseline. I tried to stay calm and not panic just like everyone here says to do. I just met telling myself that it made sense - T seems louder when you wear hearing protection, so if your sinuses are a bit bunged up, including your ears, you will perceive the T as louder also.
I know it's almost impossible advice to heed but TRY and stay calm. Stress is a MAJOR T activator, and by obsessing and stressing over it, it will turn into a vicious cycle which feeds on itself. Good luck and be well.