Well this gripped me and through awkward phrasing and irritating repetition I discovered a flat and cliche ending. You wanted honest.

My future has a mass of 6.214 grams. I know this, because that is what the digital readout of my analytical balance displays.

Interesting first line that didn't really work. You've insisted on keeping it, so you then write another sentence knowing that it doesn't make sense on its own. Awkward. Just say 'the digital readout on the analysis balance displays my future: 6.214 grams. But I still don't understand the future thing. She's giving up the drug, but its somehow her future. I'm sure I missed something, and that isn't good.

I press down and feel the first crisp fracture of the Pill. My hands steady as I begin the slow process of grinding the Pill. I am literally grinding my future into dust. I laugh out loud at the thought, but the implications of what I am doing return me to sobriety. David will be right to leave me. He deserves so much more than what I will become. He deserves what I am -- what I will have been. What I was when our courtship started.

I...I...I...I...

Pill...Pill...Pill...Pilll

Razor...get me...razor...

my face and the laughter echoes freely throughout the lab. I don’t even look around the lab. It doesn’t matter.

Lab...lab...lab...

You sound like Stephen Hawking after someone spilled coffee over his voice synthesizer.

Also... really? It's a sugar pill? How many times has that been done before? It's unrealistic as well. You're genuinely telling me that no other scientist with his/her play set never once tested this drug? Not ever?

Anyway, I've been super mean. I'm not usually super mean, honest, but I feel psychological destruction is good for the soul. So there we go. It did hook me, and this would be a very different critique if the ending were more creative. Happy writing!