I am so so sorry to hear about Max. You did the right thing as watching him suffer would have been much harder than losing him now.

The day I had to lose my beloved black cat, Magic, I did much the same. I spent every minute with him until I went to the vets.
Milk was strictly forbidden and he loved it so much and would beg for it. He had a huge bowl of milk that day. However, now, that memory warms me just as giving Max his bisquits will warm you.

Give your sweet son a snuggle. XXOO