Hugs, mama...feel free to vent as much as you want! I for one am right there with you...it can't always be easy, right? Its especially hard when you don't have as much support as you feel you need...my DP works insane amounts of hours too (he's a paramedic) and is also in school, so I basically NEVER see him.
Couple hours at a time, maybe two days a week if I'm lucky. That's not going to change at least until he's done with school in June. Add to that the fact that we got kicked out of our rental house with almost no warning so are staying with my parents until we close on our new house (which will most likely be after babies are here), my 3yr old DD is acting out horribly from all the stress and upheaval of the last few months, my XH is doing his best to make my life miserable and a super crappy pregnancy (GD, back on insulin, on BP meds as of today, etc, etc), and believe me, I TOTALLY get it! I can't even focus too much on what life is going to be like once babies get here, because I think if I did that right now I'd lose my mind.
Just know that we are all here for you, to listen and offer whatever support we can. You WILL make it through this!