Oral sex for women can be a very personal, intimate thing. As you've mentioned, it can be a very self-conscious filled endeavor.

We often have this ideal or vision of what our body should be, and I feel for women this is especially true when it comes to their vagina. I'd encourage you to take things slow, build up to it, and don't allow it to become the goal of your sexual encounters, especially in regards to him obsessing over it.

The goal should be that connection, that intimacy you share with another, both physical and mental- the one you feel deep down inside during an amazing connection with someone. Spend lots of time just being together- cuddling, holding hands, kissing- allow that to lead up to that act.

Pamper yourself before you find yourself in that situation, if you know he's coming over take a long shower or nice bath, light some candles for yourself, and shave/trim up and wash yourself thoroughly there. Or, if it's a thing you enjoy, incorporate some shower time with him after the cuddling and kissing and before the foreplay.

As I said, try not to put the weight of your sexual encounters on that specific act- focus on the intimacy that you desire to share with each other. Make sure he respects your boundaries, if you do feel uncomfortable, know that 1) it's okay to feel that way and communicate it, and 2) you can always try again another time and shouldn't allow it to damper the overall experience you're striving for with each other.

Also, the human body is weird, for both females and males. It makes strange noises, it smells funny at times, it does things we don't want it to do. That's okay, if something happens like a queef or a fart, just laugh it off and enjoy the moment. Things like that are inevitable, and the guy who will be more likely to help you enjoy it will never make you feel self-conscious for those things that do occur at times.