Welcome to HCM,
You are known case of Diabetes
and COPD, and developed a Viral infection in COPD this can precipitate acute exacerbation please take care of your symptoms.
I presume your diabetes and COPD are well controlled by treatment and care you are taking.
Best would be to see Physician to let him/her examine and see if there are already signs of bronchospasm
in chest.then If infection is there antibiotics and supprtive treatment may be required.
If other things are fine you can take Paracetamol
and OTC anti histaminic like Levocetrazine or Loratidine
Steam inhalation helps in such cases and you can go for hot saline gargles.
If there are signs of worsening of dyspnea by decreased PEFR then dose of bronchodilators need s to be increased and if necessary aerosol therapy be nebulizer
will be of great help.
These are viral infection along with allergy to you so it will take some time to get relief.
Please take care