UPDATE, still in seperate tank alone and after feeding as usual i noticed the swollen lump had nearly doubled in size. I just fed it algae pellets like i have been doing for a few months. There was also a small 2-3mm stick like thing protrouding from the swelling/lump and a white bit near the anal area (poop, I dunno?). I didn't get a photo and since then it has calmed down again, not as bad. This is REALLY starting to do my head in even more now grr

I'll try and get a photo but I know it will have gone down by then and will probably look the same as previous photo's