mog basically taking over

Y’all... I’m about to blow a gasket. What in the world do I do?!!! MOG is getting on my last. dang. nerve.
Fiancé and I wanted a small, intimate wedding with an even smaller budget of $2000. Every penny has a dedicated job. We had a guest list of 56 people. That was it. Come to find out, MOG also invited another 50 people!! How in the world are we supposed to feed 100 people?!! My original food budget was $600... and now with the math... it’s looking at least $1600 😭😭 I don’t have that much money to cover all these new people. I don’t even have 1/3 of the decorations bought yet.

We put special money aside for my wedding dress and his tux so that we could have our dream wedding attire since we want them shadowed boxed together. However, his mother has been harassing me about my wedding dress since I bought it. YESTERDAY! I cant even be overly excited about finding the dress of my dreams. “Why did you get such a large dress? You’re just going to ruin it.” “I told you to buy a second dress. Why don’t you listen to me.” “Take it back and buy 2 dresses with the money you spent on that.” “My son isn’t going to like you in that. It’s too over the top.” “At my wedding I had 3 dresses. 2 is required”
On top of all this, she’s also still arguing with me over the cake! A stinking cake?!!! Since it’s so small, we wanted a small two tier cake that feeds 39 people and I was going to whip up some extra desserts to go along with it. The groom and most of his family don’t eat cake btw that’s why we want the smallest option. MOG is continuing to call the baker behind me and tell them to not let me order anything smaller than a three tier cake. “If you don’t have a three tier cake, then it’s not a wedding cake. If you don’t freeze the top tier your wedding is doomed to not last.” Like I’m highly doubtful a cake will cause a divorce. The baker is a family friend (perks of a small town) so they call me when she calls.
Do y’all have ANY advice before I lose my cool and end up using some bad words to get my point across?! I have explained things ****x times of why I’m doing things this way but it’s clearly going right over her head. Fiancé has even said things to her as well but then they get into a heated argument and won’t speak to each other for a few days.
We agreed on the small budget wedding since we were gifted a BEAUTIFUL beach vacation (can’t really call it a honeymoon since we will be taking our two small children) and we wanted to spend more money there with our family. I feel so overwhelmed and we’re a little over 100 days before the wedding. Is it wrong to pray most people don’t show?😭 my RSVPs are due back July 1 and I’m literally biting my nails till. I worried I’m going to have to switch caterers and come up with a different meal altogether.