IMO, you got some bent fender attachment flanges it appears. You may be able to pull down the fender at the bottom with more shims, but there's likely no way to
Was it some jackwagon at a service facility jack the car up last? I mean, how in the hell do you not use the frame rails on a full frame car which are only a couple inches away from the fender? Or extend the jack pads from the lift to meet the frame before something hits the fender? I'm not judging as accidents happen, but clearances should be double checked at least before jacking up a car.
I've seen many a 4th gen F-body front fender bowed out at the bottom from unwitting/uncaring service facility (usually dealerships) employees not knowing where exactly to jack up the car. TOO many. But their saving grace is the front fender is plastic and bows out instead of up. You can rebend the brackets and get it back into place fairly easily. In this case, I think the fender has flexed upwards on the outside, slightly tweaking/bending the upper and lower mount brackets just a bit.
To do it right, I'm thinking the front fender has to come off. I'd avoid having someone sit on the fender, although it's an option if you're bold. It might do more damage. "Butt bump" adjustments aren't very calibrated. I know I wouldn't do it if it were mine.
Good luck with this.