You isolated these symptoms:
a. the bike started consuming oil
b. increased vibration of the engine
c. steady decrease of performance// the bike won't accelerate as smoothly
d. i let go of the gas i hear a clapping sound
Here is what I would suggest:
1) run a full tank of known good gas through it with no additives.
2) change oil and filter with the best stuff (BMW 20w50) mineral oil not synth.
3) insure plug wires, coils, plugs, and ignition system are operating properly - replace plugs and wires as necessary; battery fully charged and charging? - check alternator
4) do a stone cold valve adjustment (never assume the dealer did anything if it is not on your receipt, itemized) (never assume he did it right)
5) do a warmed up engine throttle body sync (insure cables are seated and operate properly without binding - check the Bowden box)
6) check cam chain tensioner lef tand right
7) check TPS settings and reset if needed (procedure for R1100? I do not know)

balance tires and wheels, inspect, clean, and replace brake shoes, calipers if necessary; check for true rotors
9) visually inspect, check, touch, re-torque every exposed bolt, nut, fastener especially shocks and wheels
Now ride it some more and see if any of the symptoms smooth out.
10) on a clean unmarked surface park the bike HOT and observe weeps, seeps, leaks for 24 hours - Note which seals, gaskets, and seams are problem areas - save notes for later
11) check driveline front to back - transmission gears fully engage?; clutch operates smoothly - no chatter or slippage; splines (yikes!); final drive?
12) take it to the dealer for a computer fault code reading
If none of this helps... seek a local, non-dealer expert for more assistance.
Many of the things I suggested are not direct to your stated problem, but at this stage it appears you have potentially unrelated problems all starting at the same time you feel guilty about the oil thing. So doing all these things (which you CAN do) helps yopu baseline the bike and get a feel for the serious problems if any. At the least, you get a placebo feeling of stuff you know you did right.
The Older I Get, The Less I Know.