Continental Grip + Serve

As of late, I have been forced to use the !Semi-Western Forehand! grip on my serves. They may be flat as heck, but at least I can put some power on it.
When using the Continental grip while serving, I can't hit the ball straight or with any power. Whenever I hit using this grip, the ball balloons, once and awhile over the net, in a crazy left spin motion. I can put absolutely no power on the serve. When I try to hit hard with the Continental grip it hurts my wrist. Any thoughts what has caused my grief?

[Mahboob Khan]

It is quite obvious that your service mechanics require fixing. Continental grip is the proper grip for serving. Seek a coach's help, get your motion fixed, and get on with your serve with a continental grip.

It takes a while to get comfortable with continental grip.

[Bungalo Bill]

Agree with Mahboob, you need someone to look to see if your wrist or your fingers are changing the racquet face to compensate for old muscle memory. Mahboob's advice is right on.