My blue betta is sick, it started with a lil swolen on his neck (looks cute at first cuz I thought he just ate too much or smth, then I read online and I realized he's not suppose to be fat) and now it's aleady 1/3 of his body is swollen. I'm afraid the swollwn will go through his whole body. he seems to have a little bit difficulty to swim as fast:( I tried to give him the bettafix remedy (it says can heal swollen betta) but doesn't seem to work. This is my first time having a pet fish, I'm so sad.... what can I do? help me, pleaseee...