I got fired and don't know if it was legal, what now?

Take a breath first. Being let go knocks the ground out from under you, and on top of the shock you are now carrying a question you cannot answer alone. That is a lot. You do not have to solve the legal part in this moment. Right now you just need to steady yourself and hold onto the facts. Here is the plain truth: some firings are unfair but legal, and some cross a real line, and you usually cannot tell which from the inside of the hurt. So do not decide either way yet. Instead, write down what happened while you remember it clearly. The reason they gave, the dates, who said what. Save every email and document you can. Then let someone who knows the law look at it. A labor board or agency in your area can often tell you for free, and many employment lawyers will talk through a first meeting at no charge. You are not overreacting by asking. You are allowed to find out. One conversation can turn this fog into a clear yes or no, and either answer is easier to stand on than not knowing.