I can't enter a server, you are not logged into your account

I {}can't get into a server, it says {}"you are not logged into your minecraft account" I've been having this problem for a long time, please I need help, I get too stressed out I can't get into the server, and I'm actually in my minecraft account, I don't understand, please help, if you need my email i drop it
My minecraft user is iSagesito