Giving Head ( for longer??? )

Okay so girls!! About two months ago I gave my boyfriend head for the first time.... and I’ve probably done it more than 10 times now. I feel like I’m still awful at it!! He always cums like 10 seconds in, so I feel like I’m only just starting to get into it every time. Practice makes perfect but practice doesn’t work if it lasts 5 seconds ya know? How can I keep my man going for a longer time while still pleasing him??