I agree with your husband, you should fight it. But first, get a ballpark figure from the attorney about his/her fee and consider interviewing other attorneys.
Since your friend did not speak up at the meeting with the boys, do you have any reason to expect her to side with you (and against her now husband) in court? Sounds like she lost her voice during the engagement.
If you know of other friends or relatives who went to the wedding, you should interview them about it to ascertain whether any of your ideas were used. See if they have photos, afterall they probably spent a fortune on a photographer or videographer and they'll want to show it off to everyone. Apparently you weren't invited, partly out of malice and possibly partly due to keep you from knowing how much of your work was actually used. You should also contact all of the vendors and church staff to find out what happened. I wonder if any of them had a similar experience with them, if any of them had problems they may even have photos to share with you.
I have to say that I don't believe that your friend is much of a friend to let her then fiance and her now husband shaft you like this. She's given away her power to a man she's scarred and intimidated by. But if you still think she's your friend, try to get her to sign a statement when her husband isn't around. If she won't do it, then she's likely prepared to lie in court for her husband.
Best of luck to you.
In Amazon sisterhood,
B.