Did you have the FSD they gave away for free for a few weeks last year? Because I felt like I was going crazy with neighbors saying it was great while I couldn't get it to stop doing dangerous stuff. Turns out they had HW4. I think the new stack or whatever is just not ok on hw3.
Did you try recalibrating your cameras? After a windshield replacement my HW3 FSD camera calibration was off and it was similarly terrible like you were describing (going way too close to curbs), but then I recalibrated on a straight highway stretch and since then it's been amazing. Over the past few thousand miles, I only take over for parking and getting out of parking lots at this point. (Also the occasional intervention if I want to take a different route that I think might be faster.)
I got 3 months free when I bought the car new, canceled and reupped a few times, but have had the subscription since they lowered it to 99$. The HW3 definitely had more hitches (sudden breaking for roadside debris, weird adjustments turning into parking lots), but I got used to it. For the "less maintained" road (piles of brush/garbage/discards) on my commute, I kept my foot over the accelerator.
There were definitely regressions with my Model 3, though the issues and improvements were at the margin.
The HW4 I'm in now doesn't exhibit those issues and does Park to Park to and from, most days without any intervention.