I have a tiger Oscar that’s around 5/6 years old and I got him when he was about 2 inches big and now he’s about 8-9in, he’s been in a 75 gallon tank his whole life. His diet consist of pellets, frozen blood worms and occasionally crickets. He would freak out randomly and make a big splash and throw water everywhere but it was normal cause there was always a reason but I noticed lately he had been doing it more frequently like once a week. Then one day he freaked out for a good minute, he was spazzing out hitting the glass and the gravel and speeding across the tank and it worried me. But as I watched him afterwards I noticed the left side of his stomach has a big bulge. I’m trying to figure out what the bulge is, I waited a week and feed him sparringly to see if the bump went away but nothing, it’s still there. I also see that he is pooping so it might not be a blockage. But I can’t wait any longer he freaked out again today. He’s hitting the gravel and glass so hard he is taking chunks of skin off himself. Idk what to do help please.