accelerating

I have a 2009 848. I took it for a ride the other day, and its been about three weeks since i've rode it. While i was riding i noticed it didn't sound clean as i was accelerating, and i could not get it to accelerate after i got to 3rd gear. I opened up the throttle and it only went 55 mph...

Not sure what is going on? I was driving home from work and all the sudden on acceleration the engine would sputter/huff/slip. Doesn't do it on deceleration and I thought it was was the engine, so I went to nuetral and reved the engine and the engine revs fine. I thought it was 1st gear but...