2002 BMW X5 Plz. Help! Engine Failsafe. Have Codes: P0455

I have a 2002 BMW X5 3.0 V6. 97K miles.

I'm new here to the forum and need some help in a big way as I am stuck outside of my home town. I was getting on the highway (was at high rpms) when suddenly the Engine Failsafe Model light cam on and was able to get off highway before care shut down. Had it towed home. Was able to drive (only in idle and the engine revs up then down but able to crawl along at a few miles an hour and brake and abs lights are on plus brakes only work manually - had to push down hard on the brake in order get close to a stop) to Autozone and got the codes. I have checked all connections under the hood and everything seems in order.

They codes are: P0455, P1500, P1632, P1638, P1639

For OEM brand volkswagen troubleshooting (closest match - there is not BMW on the printouts) P0455 says:
- BBEVAP system large leak detected. BBLloose, defective or missing fuel cap. BB1 - faulty vent solenoid, BB2 - Faulty purge control solenoid, BB3 - faulty fuel tank pressure sensor

P1500 - BBFuel pump relay electrical circuit malfunction. BBOpen or short circuit condition. BB! - Failed fuel pump relay.

P1632 - Acclerator pedal position sensor 1/2 supply voltage. Open or short circuit condition. Bb1 - poor electrical condition bb2 - failed accelerator pedal position sensor.

P1638 - no info for volkswagen - just GM and CHRYSLER - for GM says Generator F terminal circit fault. ECM has detected an improper voltage level on the generator F terminal. Bbb1 - circuit shorted to power or ground bb2 - failed generator. For Chrysler says: TCM internal can 1 ram performance. The TCM is reporting an internal processor error. Failed TCM

P1639 - accelerator pedal position sessor 1/2 range performance. Open or short circuit condition. Poor electrical condition. Failed accelerator pedal position sensor.

Thats all of them. My goal is for someone that knows what these codes add up to to let me know what needs to be repaired so I can do it myself or hire someone independent of the dealership. Car is not under warranty and I need to get it repaired affordably as possible.

Thanks so much for your help.