Spiral is right Borry mon brave. Pull yourself together, calm down, take the tablets, chin out, stomach in and best foot forward.
Here's something to help you on your way.
The Gaelic (Scots) for the highlands is Gaidhealtachd. For the lowlands Galldachd. Which means the land of the foreigners. Which means les Gaulois, were foreigners in Gaelic at least.
We know that 'O' blood groups are 'Celtic'. Sorry about the C word but think of it as aversion therapy.
However 'O' blood is the most common group especially amongst 'Native Americans' and the English and most places elsewhere in Europe. So we are all Celts.
Celts are tall and blond unless they are ginger. Celts are short and stocky and dark unless they are tall, blond and ginger. Female Celts all turn blond from their fifties onwards. Must be the genie in the genes.
Norse people tend to be 'A' blood groups which are also found in the Scottish islands. And so far we haven't mentioned the Rhesus factor. Lots of negativity in Basque country and elsewhere.
And lets not mention North Wales, the ginger ones, who tend towards the B blood group which is, I believe, associated with Asia. Whether major or minor I do not know.
Then there's language. The Celtic languages are found in Ireland, Scotland, the Isle of Man, Cornwall, Wales, and Brittany which was settled by people from Cornwall a long time ago. The 'Gallos' in Brittany speak French. And they are found in the east of Brittany across a fairly well defined border. As far as I know Celtic languages do not exist in Spain or Portugal or France or North Africa.
Welsh is not Irish. They may be distantly related but which came first? Cornish and Breton are related to Welsh. Manx is related to Gaelic, both Irish and Scottish. The Vikings seem to have quickly picked up the Gaelic language for some reason and they certainly went native in Scotland.
We know that English is not a Celtic language. Let's look at the differences.
The verb To Be in English is just that except that English does not have an infinitive, we have to add 'to' to the beginning. The same verb in Gaelic is 'Bi' pronounced 'Be' and Gaelic does not have an infinitive. It has to add 'to' or rather 'a' which means to to the begiinning. See the difference?
When it goes through the various pronouns it changes to 'Is' pronounced 'Iss'. The word for me or I is 'mi' pronounced 'me'. You singular is 'thu' pronounced 'oo'.
See how strange this language is. Of course being Gaelic it has a continuous tense system, rather like the er English way of speaking. I am writing etc which we Frenchies cannot do, nor can the Krauts for that matter as far as I know. Gaelic does use another verb to be to do this unlike the lazy Sassenachs who'd rather sit at home claiming benefits.
So, there we have it in a nutshell. The Celts are everyone who is not English and they are all heroes and blond, or ginger, or dark unlike the English who are not.
I hope that has sorted it out for you Borry old chap. If you see the men in white coats coming it will only be the local neighbourhood druid circle looking for mistletoe and a human sacrifice.