Things definitely don't add up here.
PBSS stands for Punkbuster Screenshots. It's a part of PB that we use which captures random segments of your screen while you play and reports/uploads them to the server. These can be used to detect ESP/Wallhacks, crosshair overlays, etc. Blocking them is a favorite of cheats to avoid detection. Forgive me if you actually didn't know all of this...but I kind of doubt it. Your whole story, claiming ignorance is par for the course with cheaters.
The real red flag is that your PBSS were all fine/clean until you magically got better at the game overnight...then your PBSS stopped? I don't think so. When there's smoke there's usually fire.
There's just too much out of place here.
If you want to get unbanned then you'll need to record footage of your gameplay for an entire round from the loading screen to the match completion screen. It will need to meet the following requirements:
Minimum resolution 720p @ 30FPS
3.0 K/D ratio or greater
2 kills per minute or greater
use AEK or acw-r
If you can do that and provide such video we'll consider lifting your ban.
I think you'll agree this is more than fair.