It's not a swollen belly, it's just that it was facing upright at that point
To be honest i've been looking at different pics on the internet about hole in the head, and it doesn't look the same, but i just wanted to make sure
It is actually in need of a water change, i was going to do one tomorrow, and add the medication after, as i still can't add it yet..
I can't isolate the discus as the only spare tank i've got is a 30l which would be too small