HELP!!! My Bike is DEAD

Hi Everyone
I park my bike in the corner of the parking garage, its just big enought to not bother anyone else. Well I guess it did bother someone because I found a warning teling me to move the bike.. No biggie, When i went to move it, the biek would not start, I checked everything and It wouldn't budge, not even the dash lights. So I finally pulled the seat, as i did I was the screws were pretty loose in there. I jumped it with the car ( I KNow, I know) and it started right up. I figured i must have left it in the ignition position that leave the brake light on. As soon as I pulled the cable off the bike died. So I jumped it again and gave it some throttle, and pulled the calble off again..it died. So i jumped a 3rd time and left it on there for 10 minutes or so and then pulled it. It did not die but the lights started flickering and it ran like crap. I played with the jumper cable giving it power and taking it away and as soon as i made contact it would run fine and as soon as I pulled it it would flicker and bog. I drove it around for a few minutes thinking i woudl charge, it started to run a bit better, but when I shut it off, it woudnt start again.

I checked the fuse under the seat and it was ok. But i dont think it has anything to do with it.

DO I need a new battery? Is my alternator bad? is there a bad fuse? If someone was messing with me, what could they have done to kill it like that.

I also noticed one of the bar ends is missing as well. But it could have been like that before.