So, I just moved back to Phoenix and was finally able to do an oil change myself (what a pain in the ass), and as far as I can tell, the engine seems to sound normal again. Lesson learned; always check the oil level during fuel stops and not to rely solely on oil pressure and temp as to the level of oil in the engine. Now on to more pressing matters, like changing my A/C back to R12, 'cause it's just not cutting it in the AZ heat.