Hi Tryingbest - Here's my $0.02 . . . Everyone has their preferences around how they'd like life to unfold, and sometimes those preferences change. It sounds like an argument ensued and both of you dug in your heels over how the other person should act.
IMO "behaving unreasonably" is a subjective judgment. It's thinking a person should act a certain way - black and white thinking. And, when people don't respond in a way we think they should, well, sometimes things escalate. Remove the judgment and what's left is you want him to participate and he doesn't want to. Please don't assume I condone your husband's demand that you cancel the event; I don't. However, I think I understand his position in not wanting to participate in plans you've made.
Your hubby saying, "My condition is nothing compared to yours and if I (you) don't understand him then I (you) should leave." is an off-the-cuff empty threat with the unconscious hope that you'll oblige to make him happy and comfortable like you usually do.
You'd probably prefer to avoid such silly/senseless dialog. To do so requires you to reconcile your wants/needs, and those of your family/children, with allowing him to feel and act independently. In other words, as Anthony mentioned, don't enable him. It's not your responsibility to make sure he's happy all the time. You may be able to give him those things that help to make him happy and comfortable, but in reality, you can't change his moods or his PTSD symptoms. That's his job. Taking on his job is way too much on your shoulders. Likewise, with trying to see to it that other people are comfortable.
Your hubby is not responsible for your relationship with your mom and you are not responsible for either of their feelings and/or thoughts about each other. With that being said, I don't suggest that you explain your hubby's actions (or lack of them) by telling you mom "he's selfish" - offering my perception or unfavorable opinion (i.e. so-and-so is selfish) is a derogatory statement IMO that doesn't help foster healthy relationships. Let the two of them have their own relationship: if she wants to know why he isn't involved you could just say a form of the truth, "He's feeling under the weather." Doing this removes you from enabling him, keeps your relations "clean" by honoring privacy between you and him, by not putting out negative info, and alleviates triangularization.
The opinion of any particular holiday being important is based one's culture, family upbringing, tradition, etc. The importance placed on a particular holiday is subjective also. I loved Thanksgiving growing up. However, Thanksgiving is the day my mother died - for years after I'd be in a funk for days surrounding the date and could only handle a very small, simple event if any.
My ex's family put a lot of importance on everyone getting together on Thanksgiving at his sister's. I conceded. The sister's husband was usually absent (in their bedroom the whole time). When I asked why she simply stated he wasn't up to joining us. Everyone always stopped in and said "Hi" to him, but went on about the day. No biggie. I learned later he had combat PTSD.
The Thanksgiving tradition at my ex's family was to eat a huge meal, sit around watching the TV, hardly speak to one another, yet throw out sarcasm whenever they had the impulse. Being together on Thx-giving, Xmas and Easter were the only three days of the year when they saw each other (despite living within 20 minutes of each other). :confused: After a while I came up with a tradition for our family - an early brunch, feeding the homeless lunch, then going on a hike together afterwards and/or a movie.
Everyone has the right to change their mind. Unfortunately, PTSD folks sometimes do it a lot. Simply because a PTSD sufferer changes their mind doesn't give them the license to insist that everyone else change their minds or their plans. IMO I think the majority of PTSD sufferers would prefer that supporters go forward with whatever plans they made, and not make a big deal over the fact that they "bailed out" (again). We know we can be real flaky - making it big deal (typically) adds additional stress to the PTSD sufferer's feelings of shame and overflowing bucket of stress and additional tension within relationships.
I'm not saying your Thanksgivings are like my ex's nor should they be like mine. I'm just saying IMO folks should be allowed to participate if they want to, not participate if they don't want to and not to make a big deal about it. I agree with Anthony - have the Thanksgiving you want with your children and your mom and don't worry.
Happy Turkey Day,
Drew