Arduino driving mosfets powered by a single source
You aren't applying enough gate voltage. See the \$I_d\$ vs \$V_{gs}\$ graph below from the datasheet. At 5V, you only have enough \$V_{gs}\$ to get about 1 Amp, which means the light bulbs only drop about 10 of the 59 Volts. So the MOSFET has 49 Volts across, at 1 Amp. So about 50 Watts of dissipation.