AIBU to say no to next year

Or am I just being dramatic as my sister put it?

I apologise in advance as this is a long and rambly post.

My DF lives in London and it takes 6 hours to travel there from where I live. As you can imagine I don't see my DF often.
I have two DC (9 and 7) and this year DF has been saying how sad he is that he's never spent a single Christmas with them.
My step mum is a carer for her disabled mother so they've never had the opportunity to travel to us over Christmas as SM siblings can't help look after their mother on Christmas day and leave all responsibility to SM and I can't travel to them over Christmas either because it wouldn't be fair on the DC's father to not be able to see his DC on Christmas.
I suggested that we could celebrate Christmas together just not on the 25th. DF and SM thought this was a great idea. Initially DF and SM were meant to come to us as it would be easier with my DC and give SM a break from home but we ended up travelling to them due to complications with SM Mums health. I've only stayed in DFs house once in the last 10 years so we thought it would be a special occasion.
We were there from Tusedsy until Friday and what I thought would be a relaxing getaway turned into a stressful, anxiety riddled one. And here are a few examples as to why
-SM is a clean freak. She constantly watches the DC when they eat and drink which not only makes me nervous but them also. 7yo DC accidentally knocked over a drink and began crying hysterically cause he was so afraid of what SM would say. She vacuums and sweeps immediately after they eat and by third day they refused any snacks in between meals because she makes them feel so uncomfortable when they eat.
-SM starts hinting its bedtime for the DC from 7pm onwards. They don't go to bed until 9pm on school holidays. The first night we complied as she made us feel so awkward but the DC's were so excited to be on holiday they just couldn't get to sleep and you could hear them chuckling and getting in and out of bed. I ended up going to sit in their room with them by 7.45pm because SM made me feel so uncomfortable because they were being 'noisy'. When I made it clear 7pm was too early to send the DC to bed the following night SM went to bed 7.30pm instead without saying a word leaving DF to entertain us🤷‍♀️
-DF left stray Christmas decorations lying about which the DC got hold of and bent out of shape. DF lectured the DC for ages about respect even after both DC and myself apologised profusely and offered to pay for replacement.
-DF got annoyed because they didn't play with the games and toys he's purchased for them in a 'Correct manner' whatever the hell that means.
-9yo DC has disabilities and he has difficulties regulating emotions so has pretty epic meltdowns, the meltdowns aren't constant, only when he gets really overwhelmed. Both DF and SM are aware of this and yet they kept asking what's wrong with him, why isn't he practicing, why is he being difficult and unreasonable and I feel like I've done nothing but defened him for 3 days.
-We had to follow a literal itinerary of activities/ day outs they had planned. Nothing was spontaneous and nothing was relaxed about it either. Our input was ignored and whenever DCs said they were bored I'd get blamed. Everything stank of it's either our way or the highway attitude.
-They said make yourself at home but not once did they show us where they kept anything or told us to help ourselves to food or drink which meant we always had to ask can we have this or where can I find this first. It was awkward as hell.
-SM had other guests staying this weekend they arrived the same day we left and she kept bringing it up. "They're arriving at so and so and I'll need to change the spare beds sheets a few hours before and clean the whole house" Yes, I get it, you want us gone first thing on Friday morning. Wouldn't have minded if she just said "would you mind leaving first thing so" instead of the constant hinting.
Those are only a few examples of what's been going on and I haven't been able to relax, been constantly on edge just waiting for the next disaster to happen. I've been quite short with the DC while trying to keep the peace and trying to second guess what they're going to do next that might upset either DF and SM. My anxiety has sky rocketed Don't get me wrong, we had some fun and SM has always been lovely when she visits us and she went to a lot of effort for us but it was such a disappointment.
My DF and SM said we have to make this a yearly tradition and they have more fun planned for us next year and I mentioned to my sister I wont be going next year as it just spoils the fun of Christmas and they'll have to travel to us instead and she said I was being dramatic and difficult.
I know it's a long post! Thanks for reading this far!