I took off the black trim, i belive called a-pillar, which runs up above the window and after that the headliner started sagging. Is there a way to fix this without going to a shop. something I can do myself?? thanks

 

If it is just the material sagging, the help-it section at Auto Part stores sell a headliner support screw which just screws into the board to hold up the material. Or if you make a very small slit and spray some adhesive under the material and hold in place.
If it is the board itself.........it is not very hard to remove and repair/replace.