Sounds to me-by your answers- that you are a good fish mom.......
I would start by treating him in his tank for now, start by making daily 50% water changes, clean water is the best medication for fish and it can help prevent secondary infection.
If after a few days of dedicated daily 50% water changes and it looks like it is not getting better or looks worse-
I would Qt him and start the aquarium salt 1tsp/gal along with 100% daily water changes for 10 days.
I can't stress enough the importance of water changes especially when it comes to injuries.
Also be aware that too strong of a current from the filter can be part of fin issues...like a flag flapping in the wind...so make sure the current is not too strong.
I knew you where a good fish keeper.....