Negative voltage source (-0.55V)
i have 5V


You could do it like this. Take this circuit that produces -5 volts from +5 volts: -



Then use a unity gain non-inverting op-amp powered from +/- 5V connected to a PNP emitter follower with the feedback loop from the emitter. Set the input voltage to the op-amp at -0.55 volts with a potential divider. Or use a push-pull amplifier like this: -



You should be able to get away without the NPN transistor for your application.