Translation:I am a fisher. I do not eat fish though.
So, I learned Gaelic at the University of Edinburgh, and they use a few different spellings from Duolingo. I learned to spell "though" as "ged-thà", not "ge-tà". It drives me crazy when Duolingo marks these things wrong. (Another is "Càite bheil" instead of "Càit a bheil")
I should not have been marked wrong for "I am a fisher though I do not eat fish". This the more normal way you would say it in English. The way your translation puts it would be correct but less common. You need to allow English its own way of saying things as well as Gaelic.
Why does "I will not eat fish, however" not work for the second sentence? Isn't this a continuing construction?