What would cause my feet to feel the need to be cracked n ache all the time. also losing and what looks like a bruise on my knee but goes away?

Feet cracked: That feeling is usually associated with tendons that are slipping in or out of the groove they run in. Much like cracking the knuckles of your hand - which is also a tendon moving in and out of a groove and not the joint popping. If it causes you no pan there is nothing really wrong. If it is painful or unremitting , then seek the help of a podiatrist. Good luck !