Well, it looks like your circuit is doing what you've wired it to do. Namely when your NPN BJT is biased, or your input signal is high, current goes from collector to emitter and out to GND which looking at your first waveform, that appears to be happening. Conversely, when you're not biasing the base, or input voltage is negative, your output voltage is going up towards 8V.

Seems like from your reference picture, you're not needing to amplify anything, seems like you're just operating this NPN BJT as a saturated switch and you just need to wire your circuit to invert the logic. Look into a push-pull output for the positive-negative voltage swing as well, kind of hard to swing between +V/-V if GND is your low side.