I was once let go after 90 days from a job for no good reason, but the reason was the same as yours – that my performance wasn't as good as everyone else's. It was total B.S.
The manager was hated, and a very trashy person. Educated, but incompetent, and everybody knew it. She knew nobody respected her, and that's how she took it out on everyone. She fired a lot of people. I walked out of there relieved actually, but at the same time, I was thinking “What a glorified waste of time.” I accepted it and moved on though because that's all you can do.
Look at it as a blessing, if you can. Obviously, it ended for a reason. And whatever the reason is, you just have to accept it for good or bad.
Your right place was obviously not at that company even if it felt right and things were going fine. So, it's just a matter of finding your right place. There are any number
of reasons that an employer will let somebody go and just FYI, in like 47 or 48 out of the 50 states, they do not have to tell you why. Or, they can lie to you and get away with the lie. It's that whole “at-will employment” thing….you can quit for no reason or they can fire you for no reason, with no repercussion or obligation.
Best of wishes for your new and better next job. In the meantime, do something nice for yourself – take yourself out to eat or buy yourself something nice.