Tips? PLEASE! 😊😕

I really like pleasing my guy but I'm still like a beginner to give him a blow job. I try giving him one and use my hand to Jerk him off too ( idk if it's the correct term ) at the same time or grabbing his balls. BUT I feel like i have to do one or the other. I'm really a bit off balance.

I also have this jaw problem , if I have it wide open for so long sometimes it hurts I even can't kiss him afterwards. I've always wanted him to finish when I'm down there but I never can't because of my jaw.

Any tips on making him cum a bit faster without opening my mouth the whole time?