Since he's drooling and chewing, it could be teething. Yes, he could be getting them by his age. And even before they start to erupt, they cause a lot of discomfort.
I don't think you've caused any permanent emotional damage, but his behavior could definitely also be a reaction to the time apart. He missed you, his feelings are hurt. Luckily, that age has a short memory and forgiving heart, so he'll get over it soon if that's the issue.
Best thing is to keep him on his regular, familiar routine, give extra attention. And even if he doesn't want affection, just grab him, tickle him and give him a quick kiss, because he still needs it whether or not he's willing to admit it!
His reaction is a good sign that he's very much attached to you. Otherwise, it wouldn't bother him, right? And he knows it's safe to express negative emotion to you.