Is a platelet level of 446 anything to worry about? ive read that cancers cause it and even a rare et cancer.. i have always had a platelet count of around 420. asked doc with no response yet. my anxiety is killing me. other blood counts was normal?

Assume that all blood tests have a variation in resluts of at least ±10%. So 10% of 420 is 42. 420+42 is 462. So within error rage expected. I would discuss with the lab and get it repeated. And ask why it was done in the first place.

This is only mildly elevated and may be completely normal for you. Essential thrombocytopenia is a technical way to say "high platelets of unknown cause" and, as you noted, an associated cancer is very rare. If you continue to be very anxious about this, it might be reassuring to see a hematologist-oncologist who could do additional tests and address it in more detail.