That dose does sound very high.
Ubiquinone is the basic form. Ubiquinol is supposed to be the
activated form. Ubinquinol is still rather controversial and some
think it does not work well.
This link sells both, and has information you can read.
The new water soluble type, like Q-gel at this link enables lower dosing.
Another brand out now that is more soluble is Qunol:
Walmart and Costco have this as well as Amazon.
4 months supply at 100mg a day is around $30.00
Those really high doses of older CoQ-10 that does not have
the water solubilizing quality were used in treating some PD patients and some ataxia patients. That form needing olive oil, or some fat to go along with it, is not as current as the newer
I think it is odd, that your doctor recommended such a high dose. I wonder if he knows about the newer forms?