Bj's: Any tips☺️

My bfriend and I have been into having oral sex. Either 69, he goes down on me, or I give him a blowjob. I love the way he makes me feel, especially if he is using his fingers to. I really like giving him head and I'm wondering if anyone has any great tips for me to give him the, 'Ultimate Blowjob". Make him crazy, lol, horny. He has told me that I am getting very good at doing it for him, but I'm feeling that I am not good enough. For one I gag.  And for 2 I'm having a real hard time swallowing his semen. The taste is okay, I'm getting used to it, and kinda like it, but the consistency of it is really kind of gross. If it goes up into the back of my throat not only do I gag, but I almost throw up. So for now after he ejaculated in my mouth, I have to politely spit it into a tissue or towel. I don't think he minds it when I gag, but I think he's not so happy when I have to spit it out because I'll throw up. A few times when I have swallowed it I did have to use the bathroom and throw up his semen. Does anyone have any tips for me, how to let him cum in mouth and swallow without getting sick, but enjoy swallowing his sperm. Please help me, I really, really want to be perfectly good at giving him the, 'Ultimate Blowjob' ?☺️??