Singulair and water weight

Started taking this a month ago for severe dog/cat/dust mite allergy. At first, no side effects and no improvement. 30 days later some improvement - but doesn't last very long into the day - now headaches, abdominal pain, can't sleep at night, lethargic during the day, feel the urge to urinate all day - no uti doctor said, water weight gain / yet less appetite, possible constipation, dizzy, spacey, forgetful, tingling in lips/hands and feel extremely aggressive / irritable at times during the day. SO - tonight, I'm stopping this medicine! The only thing it seemed to do was improve my allergies slightly (I'm severely allergic) - and that only lasted the morning...by evening, it was like I never took the pill (I took it 10pm every night). Oh yeah, nightmares...and I wouldn't mind ALL of the side effects / IF - it had worked great...but NO. I had high hopes for this medication which my allergist suggested/did not insist on...but am disappointed with the effects and the side effects. I read here that in 2 days off it I'll be like new...can't wait. NEVER had a migraine before I took this drug, was always a SOUND sleeper...not irritable - I'm 41 female and in otherwise excellent health. I did gain weight/but it is water weight (I can tell) and I assume it will go as soon as it came...within a week or so of taking the first NASTY pill. I welcome back my allergies with open arms...good bye Singulair.