Your math is good but the fuse will pop if it has 2 amps at 5 volts or 12 volts or 30 volts or 60 volts etc. 2 amps is 2 amps.
Analogy...
Amps ( flow of electrons) would be the volume of water flowing through the pipe. The water pressure would be the voltage. Watts would be the power (volts x amps) the water could provide (think back to the old days when water was used to power mills
