tmi im sorry

Okay so im at a loss right now. I was prescribed zofran for my morning sickness which was terrible. My life is soo much easier now. Well, minus the constipation. Im sorry this is kind of embarrasing but i am so frustrated. Ive been taking 1 4mg tablet everyday, and i havent been able to use the bathroom sense i started taking them a week ago. Im not in any pain, just so much pressure. Im bloated and my pants dont fit anymore:( i have literally tried everything minus stool softeners because well im at work from 5 am to 6pm and i dont want any "accidents" at work. 
What can i do to relieve uh. Myself? I drink plenty of water, which i pee out 10 seconds after i drink it. So that doesnt help. Ive been pretty good about my fiber intake, i love fruits and veggies, always habe. Never had a problem with it. Ive tried apple juice, cranberry juice, ive tried massaging my belly gently but nothing. Im getting so upset like i just wanna get this crap out. No pun intended. 
Can someone suggest something i can do to help relieve my problem. Lol this is embarrasing as it is, but sense you are all mommies i figured id give it a shot. I cant stop taking the zofran because i cant function without it. Please help me lol