I remember a Dusty Springfield record, 'Wishin and Hopin', where I was positive she said 'frigging' instead of 'thinking'. To my ear I was and still am completely right. My wife hears the correct cleaner version but I do like what I thought I heard!
My first thought was that the term itself was too new, but easily proved myself wrong and found the term friggin' was a much older term than I would
have dreamed. Even better looking deeper I found this which I'd never heard of before -- mostly did Greek and Roman mythology back in the day and never read much Norse despite my surname. Amazing what you find out from bizarre unrelated Internet threads
Frigg had twelve handmaidens each with specialist powers. One of these for instance was Eir who was the god’s healer and it doesn’t take much imagination to visualise a hoary Viking banging his thumb while mending his shield and screaming out. “Oh Frigg, it hurt.” Thus hoping she would send Eir to ease his throbbing digit. Hence the modern expression, “Oh frigg it” when something goes wrong.Similarly the same hoary Viking, when confronted with an enormous catastrophe like his longboat capsizing in the middle of the North Sea full of pillaged gold would have cried out, “Oh Frigg where are you. Have you deserted us? Well you can go and rot in Valhella” Obviously this is the root of the modern expression, “ Friggin Hell”, for something unbelievably surprising."