Face Fucking...

OKAY SO i’m a beginner at giving head or a blow job and my boyfriend is the first person i’ve ever given a blow job to and its NERVE WRECKING i have no idea if i’m doing anything right and sometimes he likes to “face fuck” me and it’s kinda painful cause I don’t know how to control my breathing and my gag reflex is really bad I don’t know how to help relieve it and relax..

Can you guys help ya girl out!!! I would really love your advice :)