Why does my cat suddenly different?

He is acting so weired. He left for over a week and just came home. He has lost some weight but he is a big fat cat so hes not sick. He came home and ate a lot and now wants outside again. He also like cat growls whenever i touch him. He used to like being petted. What is going on with my cat? And now I am scared to let him out again because he might not come home. I would make him an indoor cat but we kept him inside a lot this winter because he got hurt and he acted really badly when we did, he started marking and getting up on the counter and peeing in the bathtub. What can I do with him? I love him so much and I don't want him to get hurt. please help.