What do I do when my feet are really cracked on the bottom of my heels to where they bleed?

Urea cream. Over the counter creams cointainig urea or ammonium lac hydrate can help. First soak feet until soft than apply lotion. You also use aquaphor as last step to help seal in water. If it persists you may see dermatologist for presciption products.
Moisturize. Try using urea or lachydrin (lactic acid) based lotions twice daily and then moisturize with vaseline and cover with cotton socks at bedtime. It might take a while but this should help. If things don't improve you may want to have your feet checked by a dermatologist to rule out other causes.