Blowjob help

Okay so with my last boyfriend any time I would try to give a bj like I could never finish I would start gagging and tearing up and it was awful but he was always so understanding and amazing about it. But now we broke up and I’m getting frisky with another guy and like he’s not pushing me into it but like giving a bj came up and I just told him I’m awful at it. But like I want to try to give him one but literally it is embarrassing how bad I am... so what should I do? Should I just try? Like how do I improve without totally embarrassing myself??