Your glans
is naturally sensitive, which is a perfectly good thing and in fact is exactly what a young (or older

) lady's clitoris is like -
very sensitive to touch and indeed touch by an
un-lubricated finger (or indeed, un-lubricated other body part)
is quite unpleasant as that is the whole point - these parts are "designed" for lubricated sexual contact. {What
is unnatural, is to have an unprotected glans as a result of circumcision, which then - eventually - becomes adapted to un-lubricated contact and thereby, far less sensitive to sexual stimulation.}
What you are telling us here, is that you do not have actual experience of "the fairer sex".
It may in fact, be an advantage to use some lubricant (vegetable oil would probably suffice) when you are doing the stretching.