MIL hell

So I could see this coming a mile away but no matter what I did I couldn't seem to stop it. My mother-in-law has been watching our daughter one day a week for the last few months and basically doing everything the exact opposite of the way I ask her to and now that my mom is getting ready to move up and we don't need her to watch our daughter she is throwing a tantrum about how she's never going to see her and basically pulling at my husband's heart strings so that she can get her way. Not to mention that she knows this will cause us to have a fight but ya know what does she care about my marriage if she gets her way. My husband and I have been fighting about something to do with his mom watching our daughter since she started watching her and I fear if I don't get us out of this cycle soon it will be the end of our marriage. Not to mention the fact that his mom defends the nanny and the fact that she left our daughter in a swing for about 5 hours out of a day! What kind of grandma would take the nannies side on that?