Surging Idle, RPM's dropping off...........

Okay, Not entirely sure what's going, but it's been going on for about a year now and i cannot chase this problem. I've had others try to correct it for me, work done, but nothing. So I've decided to finally ask on here. Something I should've done a long time ago.

2010 GTI (things that might be important to know)
Stage II (GIAC)
Full Exhaust/Custom DP
PCV Changed due to CC (CTS)

Here are the list of problems I encounter on a daily.

Start the car and it cranks over, but then the RPM's just drop off completely and car dies. When the car starts, my idle will flutter the it's drivable until the first light or stop, the RPM's will steadily climb to 3-6k and hang there and then fall back down to 900 or so.

https://www.dropbox.com/s/fs6kg57czelm5jr/Video Apr 18, 2 46 18 PM.mov?dl=0
when EPC light isn't on, the car will drive fine and I will eventually feel a tug (surge), EPC light comes on along with the CEL (not flashing) and we're back to square one. When steady, vacuum sits right at 20. I can sustain boost when the rare chance occurs, but then I'm placed in super LIMP MODE.

TB has been replaced completely, PCV gasket replaced, CC is empty. MAF cleaned and then replaced. FYI: when the TB was replaced, I was good for about a month and it returned right back like nothing was ever done. I've searched all over before and have never gotten a clear cut answer.

The codes I'm getting are:

P0121
P0221
P2101
P0507
P0121
P2101


Any kinda help is greatly appreciated guys. Any at all.

Not sure if you tried using the wonderful world of google, but if you search those codes it appears to be something with your throttle..

P0221 - Throttle/Petal Position Sensor/Switch 'B' Circuit Range/Performance Problem

P0507 - Idle Air Control System RPM Higher Than Expected

P0121 - Throttle Position Sensor/Switch A Circuit Range/Performance Problem

P2101 - Throttle Actuator 'A' Control Motor Circuit Range/Performance