Scared to let him eat me out? Help?

I've been in a relationship with my boyfriend for 6 months and as you can probably infer, things are heated. We're both 17 so of course we love to do sexy stuff. I have let him finger me and rub my clit, but I've given him head, handjobs, ect. He's always telling me he wants to pleasure me as much as I do for him, and he keeps saying he wants to eat me out... But I'm insecure about my vagina and body.

I taste and smell myself often to see if there is anything I need to worry about, and I'm not pleased with my results. It's either my discharge is weird, excessive, and doesn't smell or taste weird, or it is normal looking discharge with a bad taste and odor :( I've been getting into the doctors and I've been getting treatment for yeast infections, but my discharge never changes. I'm getting under the impression that my discharge is normally un-normal. Also, I'm overweight by a lot, so my vagina is a bit more plushy than normal. I'm getting under the impression that my discharge is the way it is because of my weight or diet but I'm not 100% sure. He's seen mostly every part of me besides my vagina. And the thought of having his face an inch away from it makes me pretty uncomfortable.

Trust me, giving blowjobs is DISGUSTING, either his balls smell or he cums in my mouth... (Which also, ew..) and I want to tell myself that I shouldn't care about him eating me out because I don't care if blowjobs are gross, it's the fact that I like pleasuring him and he wants to do the same thing for me :/

I want to gain confidence, maybe improve the taste or smell of my vagina, so is there any good input that you guys can provide so I can have enough confidence to let him go down on me?