Have acute constipation problems. I exercise, drink 8 glasses of water a day, and take plenty of fiber in the form of metamucil, beans and oatmeal...

See GI doctor. It sounds like you are doing the right things but they are not working. This means you need expert guidance. I suggest a visit with an internist or gastroenterologist.
Try Miralax (polyethylene glycol) It's pretty gentle, is available otc, tastes fine mixed in a drink & you can take more for a stronger effect. Adding a dose of senna or bisacodyl might speed things up.