whats wrong with my betta? HELP!

Question
i got my betta fish about a week ago and when for the first few days he was perfectly fine! then one day i changed the water but after i changed it he began to shake constantly for a while and swim around rapidly. the next day i found him in the tank all still. ever since then all he ever does is float at the top of the tank or sit on the bottom under the plants. also when he floats his body is tilted downwards (his face is pointng down). can you tell me whats wrong with him? i really need HELP!!!
thank you sooo much!

Answer
Hello Jyo -

Did you use water conditioner when you changed the water?
Did you make sure the water was at least 75 F but not more than 82 F?
These are two things most people forget, and both can kill a betta. Try changing the water again, but be sure to use a water conditioner BEFORE you add your betta, and be sure the water is between 75-80 F.

Hope this is useful,
Amber Worman