Autocunnilingus is not physically possible: any porn purporting to depict it is fake. You would have to be hyperflexible and have a macro-clit to even get a small lick in as the body just doesn't bend that way.
Same and same. I have big boobs (like around a 38G)
Genuinely curious, is that uncomfortable on your back/neck/shoulders? I know that can be a fairly common problem for women with larger busts but I've never really questioned it enough to be like "What's the typical cup size where it goes from manageable to burdensome?".