True wisdom from nooka after pages of some undeserved insults directed towards the OP.
Hayjon, it doesn't sound like you and your OH have been together very long, so I doubt you have/could pretend to have a convivial relationship with his family.
If I were in your position after years of being together with OH and meeting his family etc, then I would have gone alone. Had it been closer to the beginning of our relationship, I would not have gone either. You are destined to lose either way.
Go, and you "shame" your husband and I'm sure your MIL/associated family will wonder, "Why can't she control her husband? Surely, she could have convinced him to come! Something's not right there. After all, isn't that what we women do? Use our super powers of feminine persuasion to get our men to do what we want ... she obviously didn't do her best .... poor thing, he's going to eat her up alive ... actually, no, in fact, she's a wet drip who deserves everything the marriage throws at her .... etc"
Don't go, and it's "Oh, what a terrible son we have! As for that wife of his, how dare she let us go through all this trouble ... he should never have married her ... sure, we know he's pigheaded at times, but for a woman purporting to be his wife to be so lacking in any manners or decency ... she's a harridan who is going to make his life hell .... she could have come if she'd wanted, she could have made him see sense ... etc"
At the end of the day, we women are raised in the expectation that we ought to take far more care in social niceties and graces than men, which explains why you have had so much anger directed at you by other women on here. It's our job to soothe, to placate, to convince etc. Bullshit! Your OH is responsible for his actions - if he states adamantly that he's not going and you are unable to convince him otherwise, there is no reason for you to beat yourself up about it. He's a grown man that can make his own decisions. It's easy to see why you have, wittingly or unwittingly, aligned yourself with him - after all, if I didn't know my in-laws that well, I would have chosen not to get involved. In the future, with more hindsight, you will in all likelihood regret it, but you do not have the benefit of that now.
However, where people are right in making you see sense is that what your OH did was exceedingly and breathtakingly cruel, and I would seriously examine whether this is the sort of person I would want to spend the rest of my life with. Using his treatment of his mother as a barometer to how he may treat you in the future would be wise ... he has shown complete and utter disregard for her feelings. Even worse, he has placed you in an intolerable position with regard to future relations with his family - as what is/would have been their first formal introduction to you as his wife, he has done you no favours.
Is that really the sort of man you wish to remain with? Are those the values you would wish him to pass to your own children? I am not advocating that you leave him - after all, the first flush of love can close our eyes to the most obvious dire character traits - but I hope that you go forward with your eyes open as to just how oblivious to a person's feelings he can be, made worse by the fact that the person was his own mother.