Betta Fish: Sick betta, HELP! Fin rot?

Hi, I posted yesterday night about my betta who Ive had for almost a year. He lives in an almost entirely planted 5 gallon aquarium. I do weekly water changes and the ph is 7.0 yesterday and today which is the only thing I can test without the master test kit (which im buying tonight). Yesterday my betta was super lethargic, barely moving off the floor and not interested in eating. I did a 50% water change since i cant test what exactly is wrong, and I did change the filter which I have since changed back per an awesome commenter's advice. Ive been given some great advice by a commentator that made me aware that he could be bloated from me overfeeding, but Im still trying to rule out other issues just in case. I finally was able to get a good pic of him when he was nose diving and chilling there, and it looks like blood at the end of his fins at the top which I believe is fin rot. Can someone please confirm? Will api bettafix help this?