7 + 7 = ?  
Input the result from the expression
Maximum attempts you can try: 10

Sick goldfish, please help to identify

Subject: Sick goldfish, please help to identify
by PH12345 on 9/9/2019 9:52:05

I need some help please! I have been so busy at work and haven't done the water changes as often as usual (I usually do it every Friday),I have done it 2-3 weekly instead for a few months and I do feel so bad about it...I will never do that again!
I have 2 goldfish and one of them got ill with ich a month ago. I treated with Waterlife Protozin and the spots disappeared but I noticed a bruise on its mouth and area around chin and mouth didn't look too good, it looked like the skin was white and "healing?".
after 7 day treatment I have done a few water changes, then I noticed the area around mouth looked like infected, there were red areas and on the cheeks it looked like the dead skin was hanging off (around 2-3 mm long), It was hanging for 1-2 days and then fell off, underneath skin was red and looked sore. I decided to do another treatment for ich. I used different treatment this time AquaCare Anti-fungus and whitespot.
During the treatment the spots stayed away but the poorly goldfish didn't seem to get any better, it's cheeks seemed to get a bit worse. So it happened again, small of white skin was hanging off of one of it's cheeks (another one above it's eye) until fell off. The skin underneath looks sore and pinkish.
The other fish looked fine but it scratched itself on the gravel one evening, so I decided to repeat for the third time. (I left another week inbetween the treatments and done 2 water changes).
It was a day 7 of treatment yesterday (the last day) and this morning the poorly fish has a single white spot on it's fin!!! and one of it's cheeks looks really sore and red. Please see the attached picture.
Is it's face just infected from the damage by the ich or is it developing mouth rot now? It's upper lip looks a tiny bit bruised too..(not white). Is it "hole in the head" disease? Is it's cheek just infected?
I even thought maybe it was flukes and not ich but then the ich treatment would have not got rid of the spots on it's body if it was flukes.I really don't wan't to lose it. I just don't know what to do next? Also it has had a stringy poop for a month. I have not fed them for a few days and fed them peas but no difference
The water parameters are normal.

I would really appreciate any help and advice!
Thank you!
My tank is 200 litres Fluval Roma and I have an external filter Fluval 406 (I am overfiltering).