In need of encouragement 😪 feeling so lost

So today was supposed to be a good day with the family but it turned out to be the worst day of my life. Well we were at a pool party and we couldn't find the keys I was looking thru the bags and I found them in my mother in laws bag and she happened to be standing behind me while I was looking for them the keys were stuck so I pulled them out and they swung back towards her and she thought I threw them at her so she grabbed them and when she walked away she said "Mira esta pendeja todavia me las avienta" (Look this Dumbass still throws them at me) I wasn't going to let her talk to me like that so I told her to not call me like that I think I told her I didn't throw them but I don't really remember because it All happened so fast so she tells me to shut up I told her I wasn't going to and she said really I said yes really then she told me to shut up again and walked outside. All this happened infront of people I was fuckin pissed off I was crying and shaking I had to go to the front to calm down a little. After my child woke up from her nap I apologized to the lady that was throwing the pool party for what had happened she said not to worry about it so we came home (we live with his mom & my husbands brother). So a while ago she called my brother in law and was telling him a complete different story and that I had one of my friends texting her talking to Shit to her. So my brother in law starts yelling at me that how could I do that to his mom after everything she's helped us with I tried explaining to him what happened but he was too mad to listen to me. Well she sent us screen shots of the messages that were sent to her so my husband called that number and it turns out that they had the wrong number the whole time. So now because of that it has torn the whole family apart. I've been crying more than I have ever had. I want to move out. I'm tired of living here. I have never disrespected my mother in law even from all the shit talking she has done about me. Today was just the cherry on top. I turned out to be the bad guy for defending myself. I'm honestly scared for what the future has for us. We have a 2 year old and a 4 month old & I dont know what to do😪... while all of this was happening my husband was defending me and encouraging me not to cry anymore