Seems like a case of hamusuta-tsuki, a relatively rare type of animal possession. You can expect some shortness of breath, phantom pains, speaking in strange voices and/or epileptic fits, but probably nothing serious. You're lucky, hamster curses aren't hereditary so your entire line won't be tainted. And there still might be a way to turn this curse around. You can try finding a pregnant hamster and feeding it, after the little hamsters are born you must name one, that just might do the trick.
What was the color of the hamster btw?