Risperdal making me sick?

Last night I had nausea, muscle cramps, dizziness and severe derealisation (even though I often get derealisation). For a while my heart even ached. Should I stop taking it? I've only been taking it for for nights. I also take klonopin and cymbalta. These side effects scare me (the risperdal is only .5 mg by the way) because I have severe health anxiety and fear of having a seizure or fainting. at my worst I am certain I'm about to have a seizure. It feels like one coming on (though I've never even had one). Should I keep taking the medication despite the side effects? Or does it sound dangerous/not normal?