is my lipo dead?

[Revracer]

Is my lipo dead? The plastic wrap started to bubble and its gotten fat. It just did that today and now Im worried its ruined. It is relatively new. I've had it since spetember. I run it in a vxl stampede, mamba maxed dark impact, and brushless revo. its 3s maxamps 5000. today it got really hot after not too long of running and is fat... it also smells burnt. Should it be dieing this fast? I thought lipos were good for a lot longer than a Nimh battery would be? I thought that I have been taking good care of it. I never let it get damaged. I balance charge it regularly and store it at about 40-45% charge. What is another lipo pack that i could get for less that is as good or better?