I have been taking Singulair for about 2 weeks for severe allergi...

I have been taking Singulair for about 2 weeks for severe allergies. Right away all of my symtoms completely disappeared and I thought I discovered a miracle drug. I have chronic allergic rhinitis along with some drug allergies-so since Singulair was taking care of all my symtoms, I decided not to take any antihistimines or decongestants. I am still using the cortisone nasal spray. I can truthfully say I feel somewhat depressed. I even asked the doctors assistant about it, and she was going to look into it. I feel like I don't want to do anything which is totally unlike me. Everything is a chore and I have to force myself to do my daily work. I have not had any nightmares but I can also attest to the crabbiness. It's strange - I snap at the littlest things. Also I have the tightness in my chest (daily) and wondered if it was related. Just yesterday I noticed a very strange twinge in the muscle in my thigh. It hurts everytime I walk which I have never experienced before. After reading all of your posts - I think I'm ditching the Singulair and going back to my Chlortrimeton and deal with my headaches. I feel like I can deal with the headaches better than this other nonsense....since the allergies have been a chronic problem most of my adult life. I have never felt like this before and have no reason to.