Need help!

So my husband is like any other guy and loooovvveeesss getting a blowjob, but to him it's even more than that. He enjoys blowjobs more than sex. Well due to past experiences I had issues going down on him when we first started dating. Fast forward to now and we have been together 3 years and married for 1 and blowjobs are now a fairly regular occurrence. Unfortunately, he apparently really enjoys coming in a girls mouth and that is something I just am not very comfortable with. A past assault makes me weary of it even though I know my husband isn't that guy, but I still feel weird about it. Not to mention he has a decent sized member and I have a fairly small mouth so jaw cramping is totally a thing. I need ways to feel more comfortable about it and any flavored lube suggestions that I could order from Amazon would be appreciated.