I am 15 and have only been on Singulair for a week. But I have al...

I am 15 and have only been on Singulair for a week. But I have already had sever leg cramps and my foot locked into place for a few minutes with extreme pain. I had a nose bleed today too, which is not normal for me. I have also had really bad cramping which I didn't think anything of but now I don't know what to do because I have sever allergies to almost everything outside and this seems to be the only thing that helps. After reading all this I am freaked about everything. And I have been really moody this week, but I thought it was just because I am a teenager but now I don't know.