What does this dream mean? A lot of blood?

Usually dreams about bleeding indicate that a person is emotionally worn down or exhausted from life events. Your dream is actually a bit more specific though, as the original blood was from the deer. Others bleeding in a dream can mean that they are in emotional distress or 'crying for help'. Given that the deer was the original source of the blood and that you were bleeding afterwards, your dream may mean that someone else is crying for help or is emotionally drained and that it has gotten to the point where helping them or worrying about them has caused you yourself to become emotionally drained. The white sheets further support this point, as they may indicate that you don't want to negatively impact a fragile situation (the perfectly white room) due to your own emotional wear (your tears).