The computations look a bit fuzzy, but it seems you usted a grounded emitter transistor with 500 ohms collector resistor. That kind of amplifier is very unpredictable and temperature dependent (might easily saturate with a slight temperature increase) besides having low input impedance. Of course, if you choose to use emitter degeneration, for a gain of -100 you need a x100 colector resistor, which will be unpractical. For example, for a 100 ohms emitter resistor, you'd need a 10k collector one, who would steal 50 volts quiescent voltage! For these situations you have two choices: either cascade two moderate gain amplifiers, as suggested, or use an active load: instead of the collector resistor, use a pnp or jfet current source. In the last case you'll have gain to spare, so with a bit of feedback you'll achieve both correct gain and high input impedance.
In any case, more that one transistor is required.