I'm so sorry!
Did you mean 'bad fit' maybe?
I am constantly expecting a similar fate--if misery really loves company, you have plenty, trust me. Got a Christmas retail job part-time and they decided at the last minute to keep me on, but they tell me week after week I'm not up to their standards and I'd better do better or else. Man, I work my butt off. But all they care about is selling credit cards, which I'm not so great at. I make minimum wage and have two degrees and 30 years in the workforce but it's always "you're not good enough". Ugh. I get so tired of the constant threats. Like, OK, fire me or not, stop threatening, because I'm doing my best.
I really think employers are tough right now because they can be. Hang in there! You certainly are not alone.