It was just a bad trip, you would need a ridiculous amount of shrooms to come to a fatal OD, much much more than a 1/4 of an ounce, closer to roughly 4kg's(8.8lbs) of shrooms, and 250mg/kg of bodyweight in terms of pure active chemical (Psilocybin).

http://www.clearwhitelight.org/hatter/Psilocybin.htm

You took too much man, you took too much, too much. Starving yourself for 2 days is gonna leave you emotionally aswell as physically draaaaaaaaained, and these feelings will come out in ure trip, this coupled with how much you took most probably contributed to your bad trip. 2 days without food was a bit too extensive, try not eating for 6 hours prior to ingestion, this will usually allow enough time for your stomach to become empty.