Aslief had some good ideas (no a life coach are you?)
The behaviour sounds like the husband has some issues - the meetings, service etc may be covering them over. The response to your not going suggests fear, to me - being there by himself, coming under scrutiny. What happens (maybe) is his stress levels rise because he knows he has to come up with excuses for your non-attendance. Your saying that you are not going tonight throws him into confusion (maybe) and the result is the tantrum. Think about it - there he is all contented to go, no stress, wifey by his side no pressure from anyone easy meeting, no hassle. You say 'not to night'. Red alert, shields up, confusion, comfort zone demolished excuse generator kicks in, scenarious flash before him - nosey old sister so and so - 'no wifey tonight then, is she all right, what's wrong...' and the like. All this passes before his eyes in a flash, brain overloads and tantrum fires up. (maybe). I think the real issue is not whether you are there or not but his handling it and the scrutiny and probing that he really does not want to face and all because you did not go to the meeting, 'why that b***ch, look what she has made me go through, not coming to the meeting'. I bet he drives fast and furious too to the hall.
I think you need to find out what the deeper issues are and plan your fade around them when you know what they are - I can see this spiralling out of control until he does hit you otherwise.
I may be totally wrong - they are only maybes