Betta help

[Nimue]

Hi, can anyone offer some advice please? I have been really struggling with my boy. He first had these lumps appear on the tops of his dorsal and caudal fin and the fins were severely affected, I'm a newbie to fish so I posted on a Facebook group and was advised they were most likely tumors nothing could be done (he seemed fine within himself). I recently noticed black on the tips of his fins so figured he has fin rot and have been treating for that, I have been doing small daily water changes to keep his water clean (ammonia 0, nitrite 0, nitrate 5) there seems to be some improvement in his demeanour. Now tonight I found this on him, what is it and how to I treat please? Am I doing something wrong?
He is in a 5G tank with heater and filter. Also noticed white-ish fuzzy spots on glass tonight that have not been there before, don't know if they are connected and I couldn't get a clear pic of them.
Thanks in advance.

 

[DutchMuch]

What filtration are you using? tumors you can "fix" but I don't recommend the way its done as IMO its just to risky, rather put the fish down. Uh so the way you can possibly cure a tumor is you get a long syringe and stick it inside the tumor (put the betta in clove oil) and remove the fluids. I haven't done this but I know someone on TPT who has and actually it came out successfully. several others tried it, mixed results. Fin rot also? can you get a picture of the whole tank and another of the whole fish.

 

[Ephy]

Aw. I'm so sorry this has happened to your betta. They really are so special it's so upsetting when they get sick. I really hope someone can help give you advice on his treatment. Wish the best