SLM, he is just a little confused and feeling absolutely no control over his little world. He has been bouncing around to various places too much - and you know that messes with their routines and leads to insecurity. In toddlers this means temper tantrums and angst over the slightest little things.
Start giving him "warnings" - okay, I am going to make your sandwich in a little while - why don't you run upstairs and see Grandpa and by the time you get back you sandwich will be ready - It will be bath time in a little bit, why don't you go get your pjs out and then you can play in the bubbles. Set out expectations for him, let him know what is coming, and then hang in there and follow through.
Expect resistance - but, for right now, don't give in. You know how important it is to have him on a schedule - it provides our little ones with a sense of security - they can be such little creatures of habit.
It is gonna' take a minute for him to readjust to your home and get that secure feeling back. Breathe deeply, in with the good, out with the bad, and know that this too shall pass.
God Bless