Bride has no voice

I (37F) am trying to plan a wedding with my fiancé (42M). I am 4 months pregnant and we have a shorter planning timeframe, with us ideally getting married in late Feb / early March. We initially went into this whole thing with an agreement that it would be a very small ceremony (us, our parents and fiancé’s sister) and then we would take off on a small honeymoon somewhere. I was fine with a chapel in Vegas or Reno, and fiancé was onboard with this, too. All I cared about was that I had a pretty dress for the actual wedding. Well, I got the dress last week (courtesy of my parents), and MIL and my mom came to the fitting. At the fitting my mom mentioned Reno, and MIL made a comment that Reno was “a pit”. MIL then suggested having it in a park local to her (I shot that idea down right away). Cue snarkiness and tension now between moms. I tried to deflect and change the subject since I was trying on dresses and it was supposed to be a happy time. Fast forward to this week, and now suddenly MIL has contacted several venues that she is offering to pay for in her area that start at $5000. MIL also wants to invite approx 12-18 family from her side, despite me still not wanting to really invite anyone on my side. Again, I’m preggo, I never wanted anything pricey and I do not have the energy to deal with planning (and I don’t want others planning it all for me). Suddenly now we are talking invitations and napkin colors, and a caterer with a type of food that I despise. I broke down in tears and told fiancé I wanted none of this and it is too stressful for me. Now fiancé says he does kind of like his mom’s ideas and he would like to have some of his family there for the wedding. So this infuriates MY parents of course, as they feel left out and as if they are going to be expected to pay for a wedding to cater only to fiancés family. Parents have been on my case for the past few days to either elope or postpone the whole thing (I can’t even THINK about planning a wedding while trying to figure out how to be a new parent) and it got to the point I told all parents and fiancé they were to leave me alone, not contact me or discuss anything wedding-related. Today, I just learned that my parents had called his parents and pretty much lit into them and said all kinds of hateful things, pretty much ruining that whole relationship. My parents now refuse to attend the wedding at all. I have brought up other nice venues to them in the $250/hr range but they cut me off and say that my ideas are stupid. And fiancé says he still wants to do a ceremony with family (with Reno / Vegas being a “last resort”) even after all this. I feel so lost and hopeless, like I’m screaming into a black hole. Does anyone have any advice on how to deal with parents and fiancé, or have any suggestions for compromises? I’m not even excited about any of this anymore and have given up even trying to think about it.