OK, let's look at the concepts involved here. A doctor does not tell you what to do. He may
recommend and
offer something based on his expertise in the matter which is very much a variable, and
particularly when it comes to matters sexual. Certainly he
may know more than you, but it is entirely possible that you know
more than him on specific topics, and particularly in this case if you have researched it and he has
not!
Let me put it bluntly - doctors are people and some people have deeply entrenched attitudes which influence - and impair - their sexual expression. Such personal attitudes can easily impair an otherwise professional response, in which case
you must take responsibility and make the correct choice. Unless you have cancer (rather improbable though technically possible), there is no reason to lose your foreskin or indeed, have it cut at all. There is no consent form to be signed.
As you say you have grown up with a non-retractable foreskin, it is all the less likely that you have a particular skin disease (Lichen Sclerosis) but clearly something is amiss. The main "hygiene issue" responsible for irritations of the foreskin (at any age) is permitting soap to get into the opening. You should perhaps describe to us how non-retractable your foreskin actually is - whether you can see the tip of your penis at all or how much.
Actually, a rather different "hygiene issue" at the ripe old age of 36 is the possibility of diabetes which leads to Candida ("Thrush") infestation and irritation which can manifest in this fashion. If you are perchance, markedly overweight this becomes a serious risk and (in any case) you should be tested for this by a blood test (not having glucose in the urine is no reassurance).
What else? I can't say how common insensible irritation and blood-staining is, but I figure the number of men in the world who spend a whole lifetime with a non-retractable foreskin, just as likely not realising there is anything "wrong", to be anything up to a hundred million.