My daughter is 12 yrs old and has been on Singulair for about 2 y...

My daughter is 12 yrs old and has been on Singulair for about 2 yrs. on and off but since her last Dr.'s appointment and with her breathing results the Dr. told her that she NEEDS to take the SINGULAIR every day. She's been taking it now for about 5 months straight and in the passed 2 months I've noticed a change in her attitude. I, too attributed it to a "pre-teen" thing. It was kind of gradual though, one day I was talking to her and she just blew up at me, which is not like her at all, she started crying and saying that she knows I wished she was never born and so on....I was devastated, this was so shocking to me because she is such a good kid, will help anyone and her and I could always talk with each other. I couldn't believe she thought any of these things because we have such a great relationship together. Then I noticed that she has put on at least 20-25 pounds since she's been on this and she isn't doing very well in school...I laos attributed this to "the age", she's in 7th grade and I've had numerous meetings with her teacher's who told me that it's just the grade, and how it's a big transition for 7th grader's...now I'm not so sure. I'm afraid to take my daughter off of this because she has the lungs of a 70 yr. old person...and that scares me. I'm going to have to wait until Monday morning to call her Dr. before I take her off. We've been to the E.R. several times in the last 5 yrs for her asthma and each time has been during the middle of the night, which you would think seeing as though they aren't active at that time that the asthma wouldn't act up until during the day. So as a precaution, I need to keep her on this 2 more days to see what the Dr. says. I'm not a bad mother and if I could, I'd take her off the medication right now, I just hope there's something else they can give her that's safe. I don't want to lose my daughter!