I'm guessing you have crunched enough of the wing to change the angle of incedence. You may need to shim the front of the wing up 1/8" or so. Possible you have altered the tail boom. I'm not sure how you gan mend that other than a heat gun and great care while trying to lift out the dent.

I have a Fighterbird and it is the most cantankerous and most difficult r/c model I have ever flown. It is impossible to maneuver any better than +/- 60 feet of a mark and it needs about 300 feet to make a full turn. If yours is anything like mine take heart. You'll be able to fly about ANYTHING better and easier in the future.