How do i??

Leeann • Im 19 with a 2 yr old son and had a daughter before him but she sadly passed away after a week. Im with a different man now whom i love to death and he`s great with my son. We`d like a baby of our own
I want to be able to deep throat but my man is blessed with 8-9 inches. I know they say relax your throat but idk how, I try but once it hits my gag reflex I well gag lol. Any tips to help me achieve this technique to pleasure him more?