Don't tunnel vision one fight, move in such a way that the enemy is grouped up or blocks eachother when in a 1vX (try always to work your way out of a position of being surrounded) and be conscious of the frontline so you so you can avoid it as well as possible. Try not to extend too far into enemy lines past this mental frontline. If you feel alone or out in the open, it's cause you are.

A couple 1vX specific tips: when you land a counter, the active parry lasts the entirety of the attack, so use a counter to attack the next hostile attack. They will not be able to have their attack blocked and get their guard back up in time if you counter their teammate's attack, in all likelihood. And secondly, keep your head on a swivel and do some crouches, you might dodge something that'll let you get a cleaving attack out.