I'm sorry you are dealing with all that stress.
Breathe- take it a day at a time- and try to deal with 1 thing at a time. If finishing the program is what you want to do- then do it! Don't let some advisor bring you down, and really how much would quitting now save you from tuition costs? Probably not much if there is only 1 test left.
As for the home issues talk to hubby, tell him you don't want it to just be YOUR decision and once again weigh out pros and cons of staying vs. moving. What was wrong with the add-on plan? Does he just not want to deal with it?
Also I see nothing wrong with making an area for your son in the living room to sleep as he gets older. I agree to wait to have another if you aren't planning on adding on to the house and are moving instead.
Just to let you know I didn't have my own room until I was 14 years old and I turned out just fine
I in fact shared a room with my parents until I was 4 or 5 years old because we were very poor growing up.