blue betta

a while back, not to long ago I had got two red bettas from my LFS that is
closing, they were sick and they had got into a fight at some point before I
got them (fins were a mess) and a couple people on here helped me, and they
are doing great now, fins are even looking better
so maybe I can ask one more time.
My husband will be happy at the end of the month when I will have to go
further then three blocks to bring fish home (LFS is closing) : )
They had two blue betta's (who did not look bad) but after a couple days I
noticed one had a couple spots that looked like ick, at that point I should
have looked close but did not, I started a ick treatment yesterday morning,
today I noticed that one was just staying on the bottom of the tank not
coming up to eat or anything, I got a magnified glass and was looking close
at him and thought I seen black spots but they are pin holes, now I am not
sure if in the light I was using it was ick or these pin holes i was seeing,
I think the pinholes are tail rot (tell me if I am wrong) I have an
antibiotic that says its for tail rot, so I opened the capsule and put some
in, now I don't know if I should treat with ick or antibiotic, I figure
while this is going on I will change water every day, but as of last night
it has not eaten, which is not good, anything else i should be doing?
thanks Nikki