Exhausted mama needs a break but husband won’t let me

My husband and I have a two-month-old and a one and a half-year-old, and needless to say there is never a dull moment. We are a young couple, we both work and I am completely and totally burnt out, and I need a break every once in a while. I am the one who looks after our kids the most while he hangs with his friends outside. He had reassured us that his mother would assist in giving us a break when we need it by taking the kids some days, but she has yet to hold up her end of that. she will tell us that she’s going to take the kids for the weekend, but she takes them for about two hours and brings them right back because something always conveniently comes up. Obviously she’s not obligated to look after our kids, but I hold expectation of having some nights off. I suggested we have the kids go to my moms who lives in a different state for about two weeks, just so we can get some much needed rest. My parents have time to take care of the kids and will with open arms. Because I get exhausted and want to pawn the kids off while I catch up on sleep, im being called a “shitty mother” by him. Am I wrong for needing a break? Is there anything wrong with me wanting my parents to take my kids for JUST 2 weeks?