In my opinion, you should definitely be able to drive yourself. I underwent 29 Proton radiation treatments and was fully able to drive myself - even when my better half was with me I drove. If you haven't yet researched Proton vs. Photon, please do so to educate yourself on the (big) differences. We met with several top-level cancer centers and were given multiple options from 5 SBRT sessions, 20-30 Photon, and 29 Proton sessions (or zaps as we called them. I came away confused as the experts were offering different options, willing to modify if I wanted and it was "us" who ultimately needed to do the research. We also saw the Inherent built-in medical bias as cancer centers that did not offer Proton offered reasons why it was not appropriate.......yet this was because they currently did not offer Proton and wouldn't for several years (sell what you have, not what is coming in a few years).
I came away extremely pleased with my decision to go with Proton (early 2023), I had zero side effects, other than some brief fatigue. It was the ADT that kicked my butt!

I wish you all the best as you research and make this important decision!