No worries, I am glad you both could get some rest.
I will keep an eye our for your video when you are able to post it for me.
Otherwise, that isn't a very nice means to have to check his perfusion. Though I would note that you should be able to roll his eyelid down and check for proper pink/perfusion there. Still if his breathing isn't elevated or suggesting distress, then poor oxygenation is less of a worry. And that means we'd not have to rush him in to be seen.
In any case, based on what you have told me, harsh coughing of this nature usually suggests a tracheal based issue. Common ones are upper airway infections (ie viral, bacterial, parasitic) but we do sometimes see these signs with bronchitis, asthma, heartworm, abnormalities with throat function/structure, and with heart disease (though usually a soft cough). And I would note that coughing signs overnight aren't surprising since often its when they are resting and there are no distractions that signs of this nature arise.
In this case, if this has been going on a few days, we need to tread with care. I would be keen to see his video to see if we can rule out a few of these but in the meantime do want to suggest that you can try giving a mild cough suppressant. Commonly we will give a few millilitres of plain honey & glycerin cough syrup or plain honey. These can be given as often as needed. Alternatively, you could use Robitussin DM at a dose of 1 milligram per pound of body weight every 8 hours. Of course, do make sure to only use this and avoid any with pet toxic cold medications (ie acetaminophen, paracetamol, ibuprofen caffeine, alcohol, or pseudoephedrine) here.
Kind regards ***** ***** will keep an eye out for that video link,