Hi FFH and welcome to our caring community;
It takes courage to post for the first time so good on you! I hope BB forum provides a safe and helpful space for you while dealing with problems and solutions.
You know your husband better than most. If he's had these 'episodes' before, would there be common denominators linking them?
A close family member of mine gets that way when they give in to their gambling demons. I'm not saying hubby's doing this, I'm just saying people get weird when they have secrets, whether they're psychological, emotional or behavioural.
I don't think talking to your MIL was a bad move as she has immediate access to him. Your worry would justify calling her IMO.
His angry response might be understandable due to personal boundary issues with family, but not to the extent of saying don't come home; this is odd.
Being blocked for talking about the weather's odd too. Is the dynamic between you open enough to confront him when you arrive home? About secrets I mean.
I know it's a long shot asking you to just enjoy your time with friends after what's happened, but you may as well use this opportunity to achieve what you set out to do in the first place. You deserve that much eh..
Please keep talking here if it helps you find balance. An opinion that's not linked to you personally could help you see the forest for the trees. (At least I'm hoping it does)
Take care ok. I'm here most days if you want to talk more. It may take a little while for your post to be moderated and posted, then for my response too. But if you're patient things might turn out to be productive. :-)