Would driving transformer with MCU's GPIO cause durability issue?
This is the only realistic option open to the OP - adding two MOSFETs to control the transformer primary: -







simulate this circuit &ndash; Schematic created using CircuitLab

The transformer primary CANNOT be driven from GPIO pins directly - think about the transformer primary - the average voltage across its input terminals must be zero and if one line is pulled down to 0V, the other transformer line rises to Vcc x 2 and destroys the GPIO pin. Using FETs overcomes this problem because the FETs turn off to an open circuit and allow the disconnected transformer line to rise to Vcc x 2.