It seems a bit bizarre for your husband to go from you not doing something for him straightaway, and you having a moan about struggling and making what I think is a justified point, and then him declaring the marriage is on the rocks.
I was in a marriage where I was expected to stop whatever I was doing, but if I asked my ex to do something, I always had to wait. Ie his time was more important.
You sound as if you are becoming resentful over the unequal physical and mental load, while he has time and energy for his hobby.
You mention your hormones are all over the place but don’t say how this manifests. Irregular periods, spots, low mood?
When some people argue, they say what they feel is the truth, others just want to win and will say whatever they think will get the upper hand. I learned the hard way that my ex was in the second group.
He says you are horrible to be around. Is he saying this is new behaviour? If so he should be as interested as you in finding the cause. It might be hormone/health related, or may be because you are unhappy due to unfairness in the marriage?
I would have though a caring partner would want to discuss if you tell them you are struggling, they should be asking why you feel that way, instead of just saying you are horrible.
Perhaps go and see the doctor in case there is another reason for your low mood.
In the meantime, I’d suggest start journaling. Keep a diary of your feelings and emotions, as well as what you have done in the house/kids etc and what your husband has done.
It could be that when you are feeling upbeat, you read what you have written and see that it’s all a mountain out of a molehill. Or that you are completely justified in being ‘horrible’. This diary could become the basis to divide out chores more fairly in the future.
Or you could do therapy as I did where I realised my husband had been 100% bullshitting me to so he could have the easy life.
Ref the decorator. It’s a bit high handed of him to just cancel. Even if he believes the marriage is rocky, he should still have allowed you to be part of the discussion before cancelling.
Can you contact the builder to ask if he can refit you in in say three months time? He might say no, but it’s worth asking.