Serious blow job question!

Okay ladies so when it comes to sucking dick.. How are your gagging reflexes? 
Last time I sucked my mans dick I felt like I wanted to throw up. The whole deep throat thing. Like idk, he kept saying he liked it and loved when I got messy... But I just didn't feel comfy deep throating... Has that ever happened to y'all?
Not that I'm uncomfortable sucking it, I love pleasing him. It's just hard to not gag 😓 what can I do about this issue?