Am I a bad person for not deepthroating my boyfriend?

Since kindergarten, I've had an EXTREME fear of gagging and throwing up, and I avoid anything and everything that could cause me to do either. I haven't thrown up since middle school. As you could probably imagine, giving regular head is a huge issue for me and I can't even imagine deepthroating. I don't do it often because it scares the shit out of me, and I panic. Luckily, my boyfriend is the sweetest, most understanding guy I know. I explained everything to him and he said it's fine and that he'd never push my head down or anything, and that I didn't have to do it if I didn't feel comfortable. Even though he said that, I still feel so guilty that he's stuck with me when I can't even give him head when some other girl easily could. It makes me feel like such a shitty girlfriend.  I know that the normal mentality is that if you don't give head, you shouldn't expect oral back. So I don't. But he still does it, and it makes me feel even worse. We've been together a year and a half and I've only sucked his dick a few times for a few seconds, I just can't bring myself to do it. I love him so much and it's not a matter of me not being willing to do it, I'm just absolutely terrified. Am I a shitty girlfriend? 😔