Ok you are obviously struggling so here is a clue.
Look at the context of the three texts. There is no contradiction.
Lev.11 is about clean and unclean food. It says that if a clean animal dies of itself it becomes unclean. Obviously it can't be bled but there is no mention of blood in this context. If the animal's owner buries it he becomes unclean by touching it. If he eats it he becomes unclean just the same. There was no penalty for eating it or burying it. Being unclean was not a crime. Having sex with your wife made you unclean.
Deut.14 is a restating of the same law given after the wilderness years. Again there is no mention of blood but Moses encourages the people to sell the dead animal to a foreigner. This doesn't nullify the former law but provides an option that avoids unnecessary uncleanness. Similarly the priests had additional laws that went beyond those that applied to the rest of the nation. They had to make special effort to remain clean to serve at the Tabernacle. Among these additional restrictions was that unlike everybody else eating an animal found dead was not an option for them as it was for everybody else.
Lev.17 is about blood. Please read the chapter in its entirety and notice the clear contrast. If an Israelite killed an animal and ate it unbled that was a serious crime. If he ate an unbled animal fond already dead that only resulted in being unclean until the evening.