Boundary(?) and feelings after having set boundary

Hi Brooke, this is such a wonderful format! I‘m looking forward to get new insights here about my issue.
Two days ago, my husband signaled clearly (after the kids were in bed) that he wanted to talk about some upcoming things. This day, I had done for the first time the „Throw away your to do list“ challenge – yay! and was myself in planning mode. I got to run through my things first. I asked him if he would be able to take care of the kids a certain evening in May. Without knowing, I stung in the middle of his topic, that he will be eventually on a business trip that time. Then in less than a minute a “behavior pattern” of us seemed to defold.
In my perception, he was nervous about my reaction, I felt restlessness in his body and tension in his body. He said “I am totally aware of, that I’m already on a business trip the first 10 days of May, and I know the 15th is our wedding anniversary. But, I have this new job and because you will be away for June and July, I have to cancel these meetings for sure, and I just got this dates today and I have to talk to my boss about it tomorrow and if I know your priorities it is easier for me to tell him, which date is better or not possible …”
My feelings were “not amused, resentful”, I lost eye contact and the result was: disconnection. Yesterday, I ran a model about this:
C- husband’s business trip
T- I am in a trap. I loose in both cases. If I tell him I would love to be with him at our anniversary, he might cancel but then I spend the day with a husband who will be thinking about his important meeting he will now miss.
F- resentful
A- latent aggressive, refusing, look down on the table
R- disconnection, argument, open situation

The second model was after another conversation in the morning right before his phone call with his boss
C – husband’s business trip (…)
T- I feel misused: He wants me to make his decision, wants to find arguments from outside of himself for solving his loyalty conflict
F- treated unfairly, misused
A- telling my husband. I don’t take responsibility for your decision. I am happy to help you think how you can solve this conflict for you, but I refuse taking responsibility. I want to get out of our pattern of putting responsibilities on the other (I did it way to often, too) because I think it is harmful for our relationship
R- inner freedom for myself, still disconnection with my husband

My first question is: Am I right that this is a boundary and not a manual use?

My second is: the feeling of freedom was relatively short term. I am still convinced, that the content of setting the boundary was right. I wished, I would not been falling into reactive mode but stayed calm and loving and in eye contact. The chatter in my brain restarted: he is disappointed, he would have wished more support for his new job and I want certainly be a wife that supports his husband. Maybe I was wrong?
Do I have to feel all this for the long term reward of a better relationship? Is this pain “normal” after setting boundaries?

Thanks for your answer and taking this apart!