18 month sleep regression

I believe we have encountered the 18 month sleep regression. my son is also getting his canines so teething is in full swing as well. I work kinda a graveyard shift and am 21 weeks pregnant so I am exhausted getting 2-4 hours of sleep per night. Most nights he will go to sleep okay, every morning he is up between 4:15-6:30am, and now last night was up for over 2 hours and would SCREAM if we weren't holding/touching him. I just need some help, tips, anything you can offer for how to better get through this