If you would draw a card, return a card from your graveyard to your hand instead. If you can't, you lose the game.
If a card would be put into your graveyard from anywhere, exile that card instead.
If more than one card is being drawn due to a single effect, apply the replacement as if the cards were being drawn one at a time.
It will replace itself being sent to the graveyard, and exile itself.
The second ability is a replacement effect, not a triggered ability. The card never gets to the graveyard.
The “if you can’t” in the first ability refers to putting the card in your hand, as well as being unable to choose a card. Thus, if you can’t choose a card during resolution, you lose the game.