Thank you for posting your question here, I will try to answer it to the best of my abilities.
I find it unlikely that SIBO could cause you to have vaginal dryness
. Vaginal dryness usually occurs when there is a lack of estrogen
being produced by your body. There are several estrogen vaginal creams in the market to help you with this, as to whether or not they are available without prescription in your country, I cannot say.
Once you have medical insurance again, go for a proper check up.
I hope this answered your question.