I'm going to start off with a story, and maybe you'll hear in it a story that sounds almost like yours and you can share yours.
When I graduated from college, my NM *insisted* we had to have a party (note: this party happened about a year later when things were "more convenient for her"). I, having graduated early, insisted it was not necessary to coordinate any big festivities as I was already working and really didn't have the time or energy to really involve myself in planning a party I would like (note 2: a graduation party is supposed to be in the style the graduate would like). So of course she decided to take matters into her own hands and coordinate the entire thing herself, and ultimately therefore to her own personal liking at not mine. I figured this would have happened anyway, whether I was an interested party in this or not, so I decided to not really care and just let her N not affect my daily business.
She ended up deciding to throw the party at an EXTREMELY fancy NYC establishment that is stuffy and reminds me of old Italian people and general snootiness. The walls are oak-paneled and whittled cherubs and acanthus leaves line the walls (along with gold-leafed crap and marble fireplaces...you catch my drift.) Anyone would tell you this was in direct contrast to any party I had envisioned, which would have probably included a tent, a backyard, and a LOT of Bacardi Mojito. I had to comment on my general discontent with this place, as I was hoping to invite friends and not all of them can afford the kind of gifts or attire a place like this establishment would suggest...a lot of them wouldn't come simply on the fact that it was too uppity for them. This was a problem my NM was anticipating, and probably reveled in excitement that I could only invite my seemingly wealthy friends who would give me gifts. Perhaps one of my rich male friends would even propose. Who knows how her mind works...I digress.
I was dating DH at the time and he had moved up to be with me in NY. Clearly, after all of the negative things she had heard about him through a mutual friend trying to be a horrible person, he was not going to be invited. He couldn't afford a proper suit anyway, she must have thought! The issue with the fact that I was going to be forced to leave him at home is something that still eats at him to this day.
When it came time for music, I knew I had it in the bag. My long time friend is a DJ (and even fits into her rich kid category!) and I was hoping he'd coordinate the music so I could at least tolerate the night. At this point, NM's N energy was on full-blast and she hired her own live band who play exclusively old time music with a focus on Sinatra. I think I wanted to die at this point. I wasn't able to choose the food, my guests, the drinks, my outfit, the music....NM didn't even care that I was unhappy. Think of the gifts, she'd tell me. Yeah, they were the only reason I was going to go. I was going to get the money and the items and pay off my debt and perhaps have a little surplus to survive until I got the hell out of there.
Fast forward to the actual night when I was forced to kiss DH goodbye and see his misery (I REALLY didn't want to cause massive commotion and not show up to my own party), and reluctantly endured the misery of mingling with people that make my stomach turn. Thankfully, there were a few people there that were enjoyable (coworkers, godbrother, one cousin), but besides that, it was the executed plan on NM in all of her glory. This was a fancy cocktail event from hell. It was a gathering of old rich people who liked to rub each others egos -- my NM and EF's lawyers, accountants, and wealthy friends. I could have thrown up. The music was horrible and I couldn't hide my disgust from them. I left as quickly as I could (NM had had a little bit to drink so she was a little more normal), and when she asked me how I liked the "amazing party she threw for me", I told her what I felt. I had a miserable time, I came for the gifts, and it is a shame that she can't get her ego together and let her children have their glory. Clearly that did not go over well with her, and her frustration with the fact that I could not be what she wanted culminated in that night. Since then, she has been plotting my eviction, a breakup between me and DH (didn't work so well!!), and my financial instability that would potentially drive me into the ground (again, didn't work so well!).
I probably should have stood up for myself more effectively, but I've learned a few things since then as my relationship with DH and his family has developed.