Sadly it was capped, cuz I calculated an absolute number abusing the following:
The Top Deck card is Nightmare.
You use Nightmare.
You get 7 Nightmares.
The Top Deck card is Stone Skin.
You get 12 Stone Skins.
You use Nightmare.
Deck order of opponent now is Nightmare, Stone Skin, Nightmare, Stone Skin....
Following this, you can use Stone Skin 12*7*6=504 times.
Adding the maximum number of SoD´s(12*6=72) and the cards of your deck, you will end up at
27160 HP
Maybe I did a mistake somewhere, but this amount of HP was possible.
But, well this is based on really HUGE luck...would be based, since the HP is capped now.
...if you´d used Eternity the amount would be infinite.