Need Help identifying this disease on my Swallowtail

[CmbFish]

Hello everyone, I'm hoping someone can help me identify this disease on my fish. Long story short, I just purchased a male and a female Spotbreast Angelfish. A week later the male had a spot or more like the spot was under the skin just above the pectoral fin. Prior to noticing this, the male was going at it with my Royal Gramma, A territorial thing. I noticed that the pectoral fin was damaged. Since then, the spot became what looked like an abrasion (pictured) and then a day or two later the tail seems to be infected as well. I don't have a hospital tank. I could set up one. I know I should have a quarantine tank but space doesn't allow. I have a 150 gallon 6ft wide tank with some corals and a clam. Looking for some quick advice to help this fish. No other fish has any signs of disease. The male swallowtail has a big appetite and is eating and swimming activity. Thanks

 

[Niteowl]

Hard to tell by the picture. If it’s kinda cotton ball looking it would be Lympho. My spot breast got it. I fed with selcon added to the food first. It help boost immune system to fend it off.

 

[CmbFish]

Ok, thanks so much...I will try to get some and use it and hope for the best. I'm hoping its this simple.

 

[Big G]

Another option that's specifically formulated for angels to boost their immune system: