Let's get one concept sorted for a start. Healthy
skin does not tear.
If then you are getting recurrent tearing, then the skin is clearly not
healthy, and if you developed an infection which most likely was Candida ("thrush") at the age of 20, then it is most reasonable to assume that your subsequent problems are just the same condition. I think the tearing is actually the
cardinal symptom that confirms persistent "thrush".
You did not mention itch
in association with the inflammation, pain and discharge associated with an obvious infection at the age of 18, but even if the major infection was with another bacterium, the root cause was most likely to be Candida in any case. The only other contributing factor might be the use of soap (or "antiseptics" or various other "hygiene" products marketed to unsuspecting victims). I do however have to ask whether as "a shy teenager", you nevertheless had any sexual encounters?
It is then most
important that you correct the problem of an unhealthy foreskin first, and then
consider how to go about stretching - which will be along the lines we frequently explain here. Just look back at what we (I) have explained before
regarding Candida treatment and the need to do this before
and to continue whilst
stretching and perhaps then proceeding with the betamethasone.
As to recourse to doctors, it is not merely a "very sensible idea" to consult a dermatologist rather than a urologist if one needs to for a foreskin problem, it is more like a 99% certainty
that you will not be sympathetically and correctly treated by a urologist.
The reason is absolutely simple - a urologist is a surgeon
whose specialty is treating diseases
of the urinary tract and more specifically those requiring
surgery. And he is probably (at least as one would hope,) quite good at it. But people who do not have diseases (and phimosis is not in general, a disease and certainly not an indication for surgery) are generally not referred
to a urologist, and certainly should
not be. In regards to the foreskin, urologists tend to be "one tune musicians" - you want it cut off, they will do that (though no better than a general surgeon would, if it comes to that), that
is what doctors refer people to them to have done, and that is what they do.