Baby names & MIL issues

I am 23 weeks and expecting my first baby boy!

Me and my husband announced to our parents the names we were deciding between. My parents were cool but his parents are driving me NUTS, his mom especially. She has told me that I can't name our son a certain name, because it is the name of my husbands sisters husbands brothers child and it will be too confusing for my SIL's kids to have two cousins with the same name. Every name that I liked she has either criticized or shortened it and made it some dumb nickname and it has actually made me not want to use some of my absolute favorite names. Every time we've seen them I'm they ask about names and do the same thing... The last time I saw them I nearly lost it. She and her husband chose about 50 names (no joke) that we could use that are "better" than what we have chosen. My husband seems to think it is all fun, but I am about 3 seconds away from snapping at them and cussing them out and never going back to their house again. They are causing me so much stress.

Anyone else have this issue? How did you deal with it?