Panicking in 1V1 fights

I’m generally okay at the game (my movement is very polished and my combat is mediocre) but when I’m fighting a good player and they’re lazering me, I immediately start to panic and run away or run towards them. My positioning is all over the place. I fear losing the fight cause all I want to do is beat the shit out of the player who’s sweating like crazy. I hate trudging back to the lobby with 3rd or 2nd places cause the other person is just that good at combatting me. How do I kick the habit of panicking?