Need opinions please help

Long story short I'm having issues with MIL watching my child. My 6month old has had chronic constipation since birth to the point that we have changed formulas 3 times,used every trick in the book, and have had to resort to infant suppositories once she hits day 4. Our pediatrician told us she wants us to consider a barium enema study to see what is going on as there is something underlying not being addressed. Anyways I work 2days a week and she goes to MIL house. Baby has been sick anyways with fevers, hoarseness in throat and mild congestion. I asked MIL to send me temp updates and I always send all meds,food etc that lo needs for the day. Never received one temperature reading from MIL today and I have to text her numerous times throughout the day to check on my baby as she rarely let's me know voluntarily. Asked her how she was today and had reply that she was doing great and happy. Fast forward to husband bringing her home tonight. She came in wearing a different outfit so I asked why. Husband told me that MIL fed my child mashed potatoes which proceeded to make her so sick she vomited and had to be changed. I send the only food I want her to have every time she goes over there due to her stomach issues. Since she is sick she has not been drinking nearly enough fluids which I explained how important her pushing the fluids was to MIL. Well she vomited her bottle and potatoes back up making her lose even more fluids. The MIL in my opinion lied to me and never even texted or told me about this event and my husband let it slip out. He wouldn't normally have told me either as he sides with his mom on everything, tells me I need to calm down (these type things happen frequently as she doesn't honor my wishes and does what she wants to with my child). My husband never defends me.or the type of care my child needs as he doesn't really care as long as he doesn't have to be the one to stay home and watch her himself. This isn't the first time this type of stuff has happened. Why is it so hard to respect the mothers wishes as momma always knows best for her own child yet I'm the one being called crazy and hormonal and over reacting. My MIL house stays hot as well and have asked her to not use blankets and to take her pants off once she gets there yet when I do get the rare pic sent to me she has a blanket over her and pants still on. My lo comes home with heat rash and redness under her neck where she has gotten to hot or sweaty. When she comes home her diaper is always soaked to the point of being heavy even when I send plenty of diapers as well.Am I truly the one in the wrong here to be ticked off to the point of looking for other child care? Place yourself and baby in this position and please tell me how you would react as a mom to your MIL making her own decisions for baby regardless of what you have politely asked her or supplied her to use. How would you react towards husband and MIL?