My cat ran away for two months and returned home last night...?

Go back to your normal routine. He will be fine. My cat used to do that all of time and come home all beat up. Pieces of his ears missing. He would go lay in the basement for a few days and I would bring him food and water until he was done licking his wounds. Then a week or two later he would disappear again. Chasing tail and fighting other tomcats.