emma, i have tons of advice for you. Just ask. Just because you cant get a certain medicine in the UK dosent mean you cant get ideas or more knowledge about fish. No reason to leave. IDK why some times people don't answer you. I think its rude, and shame on them. My inlaws do it to me, walk away and say nothing to me when im talking to them....and it makes me mad as hell. There are just lots of rude selfish people out there, they could at least say "i dont know" or something, but they think it makes them better than you to not say anything. I have never been like that, no matter how annoying or dumb i find someone, i still talk to them. Some people have alot of mental problems but kind hearts, and its no reason to ignore or be mean to someone. I know because it runs in my family! and it stinks!
Sine you live in the UK, i reccomend trying the antibacterial and antiparasite food options or whatever chemicals you can get your hands on like primafix and melafix.
Its worth it to find the best quality fish, food, and give them the best quality of water and care that you can so problems are less likely to arise.
Its also worth it to find fish that are attractive to you but also hardy. In another words stay away from guppies or other small fish or fancy bred fish that have been heavily inbreed and raised in sterile conditions for too many generations, once we take that away from a fish, survival of the fittest no longer applies which is why we see so many problems with sick fish. Wish you the best whatever you decide.