Guaifen-C and headache

I was taking guaifen for a sinus infection. I felt like I was dieing. It seemed like I had no blood pressure what so ever, my stomach hurt constantly, could not sleep, headache, awful taste in my mouth and was constantly freezing. I finally figured out that it was the medication causing these awful symptoms. When I looked up guaifen on the internet I was appauled that a doctor would prescribe such a thing!

My doctor prescribed this medication for a sinus infection. Usually have been prescribed a Z-pack for this by my regular doctor. I took this medication right after returning home about middle afternoon. I was awake untill 5 am went to work and took again in the AM, with my regular morning breakfast of coffee and toast, didn't eat much during the rest of the day, not hungry felt like I was on diet pills (heart palpations, etc. ).
My headache which usually accompanys sinus infections got worse so I went to bed early because it was really a very bad headache and at 5AM I woke up in a cold sweat and started throwing up. After feeling the same at 8AM Since it was Saturday I opt to go to Urgent Care. Was seen by doctor by 9:30AM. By this time I was still throwing up, horrible headach, and cold sweats. My blood preasure was at all time hight 160 over 100. Needless to say this doctor gave me the Z-Pack and he asked to see me again on Monday morning at which time my blood preasure was back to normal 116 over 80.
I will never knowingly take this medication AGAIN! Please note: 1. I have never had high blood pressure, actually it is usually low. 2. When taking medications I will always drink more water than I normally do to help just to flush out my body, especially when I am taking sinus medications as they usually "dry me out".

I took one pill last night..have not slept one minute all night long..have drank about a gallon of water and still have cotton mouth..feel like I drank a quart of tequila and ate a box of salt...dizzy...headache...nervous feeling..wish I had got online and found this sight before last night..I'm out of town for an important meeting that last all day..and have to go to a dinner tonight. They should outlaw this crap...am telling my boss to look at this sight in case I go to sleep in meeting today.. I am not in a good mood...

I am having the worst headache of my life, no appetite, can't sleep, and horrible dry mouth, and worst of all i dont feel any better, still coughing horrible and a sore throat doctor prescribed because i have a viral sinus infection, medicine making it worse.