Stress coat doesn't do a whole lot for fins...it is good for conditioning water but what aloe does for fish is somewhat debatable. The most important aspect is clean water. Fins cannot heal if ammonia is present and fish will struggle to overcome disease even with the perfect medication...which makes a water treatment that neutralizes ammonia and nitrite the best option given it temporarily stops the buildup toxins which are the most common causes of death. The biggest concern beyond clean water is preventing secondary infection. With clean water being #1, use of a lighter wide-spectrum medication as a QT preventive can take care of #2. Nitrofurazone+furan/sulfa+light meth blue mixes are incredibly popular given they provide good bacterial, parasitic, fungal, and some viral protection, and how it only takes a very small dosage for them to work well, meaning less stress. Some fish feel instantly better upon the application of nitrofuracin green, for various reasons that, in sum, makes it easier for a stressed or hurting fish to breath and utilize oxygen. As a general rule, minor-moderate fin/scale damage will heal if the fish is overall healthy, given good water, continues feeding, is kept stress-free, and is kept away from things that could cut them. Many additives such as MelaFix often make things worse rather than better, so always bear in mind that just because something is advertised as 'natural'/'holistic'/'organic'/or other common sham advertising claims, that does NOT mean safer nor does it mean any body of evidence suggests that the additive provides benefits that outweigh drawbacks of dosing. Arsenic is natural...but obviously far from safe or useful. Many of today's medications are so low in toxicity and cause so little stress that using a good medication as a first line treatment makes sense.
The doctor does phone consultations in which you can send him pictures and discuss symptoms...something that has gone this long is something that he will probably have the most experience and best treatment in mind as it is unusual. Since he would be unable to run certain tests like a gram stain, he will likely advise TMP/SMX as it's one of the best antibiotics currently used for fish. He sells TMP/SMX ranging in size from a small jar to 5 gallon buckets and beyond...Maracyn Plus is essentially the same thing, but if you order it in a jar with a scoop rather than powder packets, it will be like 1/10th the price or less.
TMP/SMX is common and many know it as Bactrim (used on people and pets...many people sell it under various names). If you use TMP/SMX, you will not need to cocktail with other antibiotics because its range is incredibly wide and it is incredibly effective. TMP has not only strong anti-bacterial properties for both gram positive and negative, but it is also active against some fungi, protozoa, mold, and even viruses...this is one reason it is ideal over minocycline given it treats more things and maximizes the chance it will treat any illness. For people, it is used to treat things like MRSA, eColi, and even VRSA, when other antibiotics fail. If fishy has a bacterial infection, chances are TMP/SMX will kill the bacteria (and also help some if it is certain fungal, mold, protozoa, or viral infections).
The doctor's medications are amazing...there are a few good makers but their combination of range of products, abilities to help diagnoses, treatment advisors, fast shipping, cheap pricing, and wide range of quantity had me using them as my primary vendor for meds and advice when I got stuck back when I worked in the industry. Gary and Brian Aukes (both doctors) have really pioneered a lot of the field by bringing high quality pharma-grade meds to the market for availability for anyone from a professional breeder to a hobbyist with one fish, and have each been a massive component to modernize treatment models by moving away from older, harsher, and more toxic treatments to the newer, better tolerated, far less toxic, and more effective medications. They were also one of the first to show factual evidence that the use of salt for freshwater fish beyond only the shortest of durations has the potential to be incredibly harmful as well as how salt really doesn't work
. Medium- and long-term usage of salt can lead to physical changes incorrectly diagnosed as dropsy, septicemia, and even fish TB due to sometimes severe and permanent internal organ damage partly due to osmoregulation being completely screwed up by the salt. Kind of like if a person gets a staph infection, drinking 5 liters of sea water is not going to kill the bacteria, but it will harm the person. All those websites that say to use salt are wrong...salt kills freshwater fish and the medications that do what many people (incorrectly) believe salt can do are far, far, far, far, far more safer than salt. Between poor effectiveness and potentially severe long-term health consequences, in a world with safe and effective medications, there is no reason for its usage as a first line treatment whatsoever.