How much sleep are you getting?
I am not sure why, if you have to do a report after class, that means your hubby doesn't get sleep. Not many teachers assign three hr of work due the next day. When it comes to homework and reports my suggestion would be to do a couple of hours every night.
If your husband has to look after the 4 month old anyway why are you sending the other child to preschool? Maybe save yourself some money and cut out that. Then perhaps you wouldn't need the 3 hr a day job you do in the morning and next semester switch your classes to morning ones. Then hubby does a little childcare until you get back.
You also need to make sure that you have applied for all the financial aid you can AND a bunch of scholarships
. There are tons of $1000 to $500 scholarships out there.
I would seriously seek the advice, face-two-face, of a financial counselor at your school/college. Plus they have info on scholarships.
That is my two cents.