Singulair and weight loss & insomnia

I've been taking Singulair for about a month now. I have taken Advair in the past but it never worked for me. I have chronic bronchitis and asthma (which is induced by allergic reactions and cold, dry weather). Singular in combination with the Flovent inhaler has really seemed to work for me, though.

The problem seems to be, however, than when I take Singulair right before I go to bed, it keeps me awake for several hours. I NEVER have problems sleeping. Ever. I'm losing weight, also, food still tastes good but I just do not feel the urge to eat as much. I notice I'm hungry when I become nauseous. I sometimes feel like the lack of food on my stomach might also contribute to the insomnia (that empty stomach feeling can help keep you awake).

Can anyone give me any information on possible side effects of combined use of Flovent and Singulair? They are the only medications I am taking other than my emergency inhaler, which I rarely need anymore (this is impressive for me this time of year - trust me). I did quit taking birth control about 1 - 2 months ago as well, but I quit taking it a few weeks before I started this regimen and I didn't notice any problems with insomnia then, either. I did notice a little bit of weight loss.