You have between eight and ten cards in your hand.
Steps
Proceed to your cleanup step, causing you to discard down to your maximum hand size and remove all damage from all permanents.
Feast of Sanity triggers for each card discarded this way.
Resolve the first trigger, dealing 1 damage to Flumph and causing you to gain one life.
Flumph triggers, causing you and an opponent to draw a card.
Repeat from step 3 as necessary for each remaining trigger.
Once all triggers have been resolved, and all players pass priority, another cleanup step will occur, causing you to discard down to your maximum hand size and remove all damage from all permanents.