Oh WOW Tia,
I am so sorry to hear about what you are going through. I have been in the same position, and done it ALL while my now Ex-Husband was on the road (he travels 6 months out of the year).
May I suggest something? MAKE HIM READ THIS POST!! You are running on FUMES right now, and you are 100% justified in feeling the way that you do. You don't get any time to "play video games." How UNFAIR!! You need an outlet as well, and it's time for Hubby to put the controls down, and own up to his share of the responsibilities of your Marriage.
One thing that you MUST do is stop staying up until 3am. There is no way that your body can re-charge, and that is why you are at your wits end. YOU have to take care of YOU, in order to be able to care for your Family. You are a top priority here, and your Husband needs to understand this immediately!
If something happened to your health, I'm sure your entire household would go under.
If you quit the Hospital Job, would it significantly affect the Household finances? Give him an ultimatum.....tell him that he can either pitch in and help take the stress off (so that you can get your work done at a reasonable hour), or that you can quit the Job.
I'm not one for Sugar coating, and I WILL tell you that this IS a wake-up call. Your husband expects you to do it all, because you're strong, and he probably has no idea that you're under so much stress. Let him know, because if you do not, the built up resentment will start to affect the Marriage.
This is one of the things that I resented about my Husband. He sat back and watched me do EVERYTHING! I divorced him (because he was a Serial Cheater) and now he knows how to do NOTHING when it comes to our Daughter.
Don't let this happen to you....TALK it out.
Good Luck!