NO, the fuel pump is not gone, its there making the noise you hear. LOL
You might be able to replace the bearings in the pump and save a lot of bucks. If it doesn't hum and the car quits running, try tapping the pump with the hammer in the MB tool kit. That trick got me home from OH onetime in my 300SEL6.3. I guess that's why MB put the hammer in the tool kit, because I never used it for anything else.
If you are going to repair the pump, the quicker you do it the better because the pump is destroying itself and if you let it go too long, it may not be repairable.
P E H