My Betta Fish is Sick :(

Question
I have a little betta fish named Monet and I unfortunately was very negligent with his water changing during this past semester that I was in college because I was very busy. No excuse I know, I definitely could've made a little time. The tank does have a filter but it still got very bad and I feel terrible. It's squeaky clean now but he's developed popeye and his scales and fins look terrible. Besides the popeye, which is easy to diagnose, i'm not sure how to identify all the stuff he has. Is there any comprehensive treatment you could recommend that will cover most of the diseases that result from a dirty tank?
I tend to be a bad pet-mommy right now considering work and school but I love my little fishie and I'm so sad that he's sick. So any advise you can give me on how to make him better would be greatly appreciated.
Thank you so much.
~Ashlyn G.

Answer
Ashlyn,
Sorry to hear your Betta is not well. First off, what size tank is he in and does he have a heater. The smallest tank he should be in is 2.5 gallons where a five gallon is better. If the tank is smaller than 5 gallons, the first thing I would do is remove the filter. They are not needed for Betta's and tend to give a false sense of clean tank water. Also, it stresses the male Betta because it makes it harder for him to swim. As for the heater, his water have to be 80 degrees at all times. I am concerned about the scales. If you look at him from above, do his scales resemble a pine cone? I am hoping it is not dropsy, but pop eye is the final stage of the disease. Unfortunately, dropsy is not treatable but very preventable. He is probably also suffering from fin rot, which is 100% preventable. Here is my number, call or text cause it will be faster than trying to catch me in here. (541) 643-9234. I will apologize for the southern accent ahead of time. I can be quite difficult to understand. Let me know as soon as you can and if possible, upload a picture to hear to that I can see what he looks like.