Why are my p-channel mosfets cutting off in LTSpice even though Vgs is negative?
why are my pmos gates not opening even though Vgs=-2.2?


They are opening, but you have selected the default PMOSFET which is very weak. here is a plot of ID vs. VDS with VGS = 2.2V. The FET is saturated at only 50uA.

 


To switch higher current you need a FET which has much lower RDSon so it stays in the 'linear' region. Right-click on the PMOS symbol and pick a New MOSFET with appropriate parameters, eg.:-



The SI4463DY drops less than 0.1V at 5A, so it should easily handle the maximum expected load current in your circuit.