I don't know what might be a vaginal blockage in your case, though I do notice a small bunching of internal tissue, on the top side, just before the G-spot. This tends to smooth out when arousal pulls the vagina upwards.
The toughening of the hymen area is definitely a difficulty. The only thing I can suggest is practice, practice, practice!
I know nothing about reactions to latex. Almost never used the stuff.
Probably we need to look up Hulda's recipe for lubricant, just in case.
How are you fixed for erotica? You might like some of the material at http://www.erotica-readers.com. Some of the subjects I don't bother with; but some are heavenly.
Lots of people love the same things. I find that very enlightening. I'd love to run a poll here. The ' p 0 r n o g r a p h y' industry is missing their greatest source of income, I think.