Need help from my DH

Amanda
My husband has a demanding job and works about 50+ hours per week.  I've quit my job to stay home with our 7 month old.  The pregnancy was not planned and threw both of us for a loop.  Our son is a pretty easy baby during the day, but he's a handful at night (waking up 3-7 times per night). He also rarely naps more than an hour each day despite my best efforts.  He's been this way since he was born!  We have tried many techniques and seen specialists to try and increase his sleep to no avail. 
My husband has only helped me with him overnight once since he was born, when I had a bad stomach bug, after begging him to do so; he then held it over my head for weeks.  Not even at the hospital was he willing to get up in the night to help.  I have asked for help many times since then to no avail, and am constantly getting sick & feeling depressed.  My tinnitus has gotten markedly worse, too.   I just don't know what to do anymore.  I think about bedtime and I want to cry.  I think about having to get up for the 5, 6, 7th time for the baby and it makes my blood boil. 
He's a good husband and father in every other aspect.  But with this, I feel like I'm drowning and he isn't taking me seriously.