I have been taking Singulair for allergies for about 4 months now...

I have been taking Singulair for allergies for about 4 months now. I have been feeling very lethargic, achy, crabby and out of sorts for the last couple of months. I have also had an upset stomach, nausea and cold sweats here and there. I never really got headaches before taking this medication. I have been getting headaches every day as well. In addition to all of the fun stuff I listed above I have also noticed a bit of weight gain and bloating, but it's difficult to pin that definitively to the Singulair. I have a scheduled doctor's appointment next week to asses the situation. It just occured to me today to look up the side effects of Singulair, as it is the only medication I am currently taking. Upon reading other people's stories on this site and contrasting them to my own symptoms I think I am going to discontinue use of this medication. I have factored in other influences in my life and I have not had any changes in stress levels or other outside influences to attribute the symptoms I am experiencing. Thank you to everyone for posting!