For the past few days my oscar has been inactive. He lays on the bottom of the tank doing and eating nothing. I though he was being moody, as oscars tend to be and would eventually come out of it. Well today I wake up and he is swimming around the tank, slowly, but swimming none the less. This afternoon however I am watching tv, and hear him thrashing around in the tank. I look over and he is spazzing out, almost like convulsions. This lasts for 7-10secs. Once it is over, he hangs vertically head to fin and does a mini spiral to the bottom of the tank. I can see that he is bleeding some, probably due to runnning into something in his convulsion. He then lays comletely on his side. He swims slowly to the back of the tank and lays completely belly up, I have never seen a fish lay belly up like this. He fixes himself to right side up, but drifts back to belly. I go to make a phone call to try and find out what is happening. When I turn around he is on the other side of the tank on his side and trying to stay right side up. On my way out the door to the fish store for help, I see that he is now at the back of the tank next to a big rock trying to stay right side up next to it, but continuing to drift belly up. The store owner told me to start with changing the water again, and turning the heat up a bit, to 78.

I am freaking out because I do not know how to help him. Have any suggestions?

Welcome to OFL,
First of all we need your water readings (ammonia, nitrate, nitrite and ph), your tank size and tank mates.
get them on here asap and we'll be able to help you from there.

ammonia - .25 ppm
nitrite - 0 ppm
ph - 7
Tank size is 100 gallons, and the only tank mates are baby live breeders, two small feeder gold fish, a plecostamos, and a crayfish.
I don't have a nitrate reading, I was only aware you could do nitrites. Since i last wrote, he spasmed one more time.

I take it your using one of those test strips that you dunk under the water?
i advise you to get rid of that asap because they are rubbish, you'll need a proper water testing kit, theirs loads of them about which you can purchase online.
also,
ammonia must be nothing higher than 0.
how long have the fish been in the tank? and did you do a full cycle before putting them in?
like the pet shop told you, do regular water changes, this is fital.

take a look at this link and see if it matches any of these...
it sounds to me it might have swim bladder disease.

www.fishdeals.com/fish_diseases/stressdisease.shtml

you have been covered by glen2009. in addition to that,
when was the last time did you change you water? there is
possibility that your o is suffering from ammonia poisoning.
have you notice if your o is breathing heavily? spasms or darting
is a sign that your fish is trying to shake off something.

for an establish tank, there should be reading for nitrate,
a by-product of nitrite after good bacteria break them down.
most of the time, nitrate level is the basis for water change
quantity and frequency.

Sounds like your oscars got a swim bladder infection and will need urgent treatment to prevent it from stressing out. I would recommend you go to your local aquarium shop ASAP and get some treatment. most treatments take a wk or 2 to work. i have used "interpet" for this problem before and this worked.

Diagnosing swim bladder disorders : look for
fish floats to surface unable to swim down
fish sinks to bottom unable to swim up
fish unable to swim upright and rolls to side to side.
fish may lay hard on bottom.

swim bladder infection is caused by viral/ bacterial infection. treatment "interpet" anti internal bacterial No9, add aquarium salt and raise temp 80f-28c. Its not a great problem to have and there isn't a sure cure but the quicker you act the more chance you have of successful treatment.

I am not a trained vet so if in doubt about this seek advice. without seeing the fish in person I cant say for sure its this. best of luck.

I have got a jade cichlid that I think it has some kind of swim bladder disorder. He finds it very difficult to maintain buoyancy and spends most of his time near the surface of the water. The only reason I haven't humanely killed him is because he is eating okay. If your Oscar isn't eating and the situation carries on like this for too much longer, I really don't think there's much that can be done. But monitor things for the next few days, you must however keep your water in excellent condition, your ammonia is far too high and that definitely isn't going to help matters.