Walls and Ceilings - Drywalling over tongue n groove, etc.

we have been working on an attic in an 1900 farmhouse. The attic area was tongue and groove. To add insulation, wall studs were added on top and insulation put in. Now, there is a problem hanging the drywall. The walls were obviously uneven prior but no correction was made. When hanging the drywall, nothing is even. We started on one end and it will be even with the wall then bow out. Think of hanging it perpendicular, yet the sheet of drywall flares out making the sheet appear to be small ramp. Wondering what can be done. Would hanging the drywall vertical help reduce some of this given the situation?

have mercy when answering...we are just a small group with minimal experience trying to finish an attic for another family who can not afford to hire any contractors. thanks....

Lol, Hello!

To fix the bowing you can either shim the joists or sister new
2x's to the existing joists/studs to create a nice true surface.

how were the studs put on the paneling? are they flat or on end? How are they nailed on? Sounds to me that you are going to have to re frame the room. You can either knock out the old studs or sister new ones on, as 'hotinokc' suggested. and sistering means to nail new wood to the old wood. but it all depends on if the old framming is put up correctly.