I agree with much of what's written above, and am sorry you're struggling so. I did want to add the perspective that it's ultimately your responsibility to take care of yourself, both for yourself and your children, that if you know you're not well enough for the trip, you can choose to admit yourself or consider other ways to take care perhaps, rather than blaming your husband for not doing it.

If your therapist told you you weren't well enough, and you seem to agree... please act on that instead of giving them the responsibility for it. As you mention, it's hard on your therapist and your husband may not be in a place to decide, though it sounded like he was trying to be supportive by accompanying you on the trip instead of just letting you go it alone knowing that you weren't feeling well....