Big Disease Problem?

[fish kid]

I recently bought a coral beauty, (about 3 weeks ago), today i noticed that it seemed to be swiming quite acwardly, i watched it closly for about and hour and i noticed that it tends to swim side ways, and it had not done that very much before, it also seems to be bumping into other fish. I really like this fish but if it is sick i want to get it out of my tank before and of my other fish are harmed. Any suggestions on the diease or treatment would be really helpful.

 

[sydney]

I am not an expert, so keep that in mind. But could it be swim bladder disease? It could be another disease that is causing it to swim erratically, because it's on the verge of dying...but if you can't see anything else wrong with it (other than the swimming), perhaps it's swim bladder disease.