‘Doctors ordered not to write mask exemption letters for those with asthma’ – even though masks are particularly dangerous for people with respiratory conditions

Dear Mr Mangnall,
With my increasing years I’ve found myself suffering more and more from asthma and respiratory problems.  Having tried putting on a mask I immediately found that it was not good for my breathing. So, realising that wearing one was going to be compulsory in all shops and enclosed spaces a week on Friday, I today approached my local Health Centre to ask for an exemption letter so that if challenged I could prove my legitimate reason for not wearing a mask or covering.
I was truly amazed and indeed exasperated when I was told that the doctors I see have been specifically instructed by the NHS hierarchy not to write any exemption orders at all for people with medical conditions (see email below).  How can this be correct?  Especially when Hypoxia (a lack of oxygen) and Hypercapnia (too much CO2) are clearly recognised as real problems that some people can have from wearing masks.
And then, when I did my own research, I discover that many medical people are also very concerned such as this medical paper https://www.primarydoctor.org/masks-not-effect. The final paragraph says it all:
The foregoing data show that masks serve more as instruments of obstruction of normal breathing, rather than as effective barriers to pathogens. Therefore, masks should not be used by the general public, either by adults or children, and their limitations as prophylaxis against pathogens should also be considered in medical settings.

With further research, I also find that the Scottish Government is refusing to confirm that any sort of Risk Analysis has been done for compulsory mask wearing in Scotland.  The obvious question here is, has the British Government done a Risk Analysis?  And if it has, can you please send me a copy. If it hasn’t, then clearly we have a real problem here which must be immediately addressed before mandatory mask wearing in England is imposed upon those who must be considered vulnerable through having respiratory problems.
I hope you don’t mind but as this is extremely urgent I’ve copied in the Secretary of State for Health.
With kind regards,
Justin Walker