I dont know much about your situation with your husband, but its worth going on the council list as you may get housed, however as you own a property u may have to force a sale thro on that before the council will consider you. its a pain in the ar*e i know, but its the way some councils work. however you should be able to get into a refuge or sheltered place, maybe the council will pay for a b&b untill you get the house situation sorted. usually once you are 'homeless' you will get rehoused pretty quick as local council like to keep their homeless figures down as it reflects well on them, the council here aims to rehouse homeless people within 30days. I know it isnt what you want, but when i was homeless i was rehoused into a brand new 2bed flat. so you dont always end up in horrible areas. however most councils will insist u take the 1st place offered as you need a home.
dont worry about the odd ciggy, even tho i've quit i still want one when i'm stressed and you sound very very stressed.
if and when you go to the council, if they accept you onto the list, make sure u fill in a medical form as well, as i would say you being depressed is caused by your housing situation. It may seem like the easiest solution is to go back, but belive me it isnt. if nothing has changed with regards to your feelings towards hubby then in a few months/years etc the hopelessnessw will return and you will find yourself in the same situation with 4kids in tow. just remember your baby is safe in your tummy atm, and is being cared for very well by you and is in the best place right now.
best of luck.