In the two years you've been here, you were ushered into a driving position with no PT experience. That in itself shines a bit of light on your situation. Most people work PT for five plus before seeing a driving position. It'll shift your disposition a bit.
Take this for example: PT supervisor has an employee with liver problems, he has soresis all over his arm. I don't know this, but the supervisor does. I ask a few questions about the guy, and find out he's a raging *******. I ask not to work with him, since I assume it to be ringworm, the supervisor tells me to go back to work because its nothing to worry about. I talk to my shop steward, he tells management that if they can't produce a doctors note to verify it to not be contagious, the employee has to leave. They tell the guy that I (by name) said he has ringworm and he needs a doctors note before he can return to work. Later I found out , through the ******* guy, that they had processed an FMLA paper for his liver condition. So they knew, created a big mess, simply by refusing to say that the guy has a medical condition. I didn't need to know anything other than that they knew of a medical condition, that was not ringworm... instead they tell him that I said he's got ringworm and he needs a doctor's note telling them it's being treated.
Stick around long enough, being rear-ended by others is bad, but when you're rear-ended by your own supervisors that'll be enough to make you bitter.
Since I assume you skipped the PT gauntlet, I could see how you could view the establishment as peachy.