I've been having a major problem that's killing me mentally and making me super frustrated. If I have a perfectly symmetrical plane and it keeps tilting to the left or right slowly and when I pull up it tilts even faster and I can't turn. How in sams hell do I get that to stop?!
Move your center of mass to the front.
try taking the cockpit off and rotating the plane, that should fix it, otherwise I'm pretty sure there is no other way to fix it