Hi Op. You asked yourself in a recent post, why you're so bother when it's just stuff?
But of course this is going to disturb you. It isn't about the 'stuff'. It's about the fact that your DH is lying to you, as well as apparently wanting to upset you, disturb you, make you think you're going mad. Hiding some cream from you is deply distrurbing - the thing you need to give you some relief from discomfort and pain - he's hid. This makes him seriously, worryingly cruel.
And it is him doing it, ofcourse it is. You've ruled everything else out, so it has to be. And you already know he's happy to lie to you. You know he's taken stuff from your fridge when you were dating, and denied it. He was doing it then, all those years ago - moving things and denying it. He's doing the same thing now.
And then look at the other evidence - when you mentioned the police, he suggests dining out when he doesn't normally. He's trying to butter you up, to prove he's a great husband so it isn't him.
The chocolate bar mysteroously reppaears after he appears back in the house. And he finds it (amazingly, it was the first thing he thought of - locating your chocolate bar, when otherwise he doesnt't seem bothered).
So-
-you know he has long time form for lying, and specifically lying about moving and taking your stuff
-none of his stuff is being moved (rules out woo or someone else breaking in)
-the chocolate reappeared when he reappeared, in a place where you know it wasn't when he was out
-he acts worried when you talk about reporting to the police
Just the lying is enough to divorce him, even without your stuff going missing.
But the stuff going missing is even more worrying. It means he's playing with you, enjoying your suffering (including a medical issue!), enjoys seeing you confused, you thinking you're losing your mind.
This is really worrying.
In the short term, I would do what a pp suggested, and check specific stuff regularly, if you feel you need more evidence that it's him.
I would also stop reacting to things going missing. He's doing it to get a reaction, to upset and confuse you. If you don't act upset and confused he won't get his kicks. He might even give his game away by trying to find out if something is missing (when he knows it is). Act as though nothing is missing.
And I would seriously reconsider if you want to stay with this man who you can't trust, and who is acting against you.