What exactly are you driving the gate with? You say 2v, but does that come from a large power supply?
You really drive the gate with a current, which means a voltage supply with a resistor in series. If you apply 2v from a large power supply with no resistor you could blow the triac gate out. Dont know if this is what happened, but it could.
Triac will keep the 'connection' if there will be a current flow from anode to katode even if you take out voltage from the base so it does not behave exactly like relay.
But for example mosfet will kill the connection if there will be not enough voltage on the gate - same behavior as relay.
You can also use transoptor if you want galvanic isolation from the power circuit.