I have a similar experience with my dad. However whilst I did nothing, my sister did. The result was that my dad suffered a very long time, and eventually ended up locked in, unable to communicate, before we eventually pulled the plug. Bring locked in was his worst fear. The last conscious communication my dad had with me was him staring into my eyes and shaking his head, unable to speak because of all the pipes down his throat, in his lungs and his stomach. Bags of piss and blood hooked up to his bladder. He wanted to die and we wouldn’t let him.

Do not beat yourself up over this. Regret is a terrible thing.

Please don’t blame yourself buddy.

As a side note, my dad also got me into star trek.