AITA for my reaction

Backstory:

My husband and I have a child who is terminally ill. I am the provider of 95% of his care right now as my husband works a ton of mandatory ot. One particular night he just told me he was going to go to the gym, no heads up, just straight up told me minutes before he left. This one night was the only night I would have been relieved of the typical nightly duties of caregiving for our sweet boy. So, naturally I was disappointed and didnt give an eager cheer of support. I paused and said "ok". I tried to push down my disappointment as I understand his need to workout and didnt want to get in the way of that. He then said nothing to me and left for the gym. He continued to not talk to me for 6 days. I, at the time, had no idea why. He just stopped. He has done this before where he ignores me/doesnt talk to me when he is upset with me, but never 6 days. After he broke his silence, I asked him why. He said that when he told me he was going to the gym that night, I had a "dark negative energy about me" when i paused and said ok. I told him that was the only night I would have had to myself in 12 days. He said if I would have been more vulnerable in that moment he wouldn't have reacted that way. Am I in the wrong here?