All right, here is a freeloader's advise
Usually housing is the major cost.
If you are religious, you may ask your church for help with housing. Sometimes they have dormitory style living quarters for those in need. In exchange you will have to go to masses and may be help around a little... but if you are religious anyway, that should not be a problem
Ask around, may be someone needs a house sitter for several months, close to the date of your fiance's arrival. That's a nice free housing for you
Otherwise - move in with your parents/siblings temporarily.
You could ask for a room in exchange for work. Often times you can get it at horse stables. Your fiance could babysit in exchange for a room for two of you. Excellent experience for handling your future children, LOL.
For immediate expenses:
Sell your no longer used stuff on Ebay or through Craig's list. That can be done by your fiance once he's here...
See how you can cut your current bills in preparation for future tough times. You do not need the following: cell phone, cable TV and I-net. Yes, I mean it

You surely LIKE them, but you can use free I-net at your school and watch only the free off air channels. Surely you have friends who will invite you over if there is something you *must* see on the cable!
You can take a student loan, invest it for now into a CD account and use it when your fiance arrives.
Find out if you can add your SO to your student health insurance plan and how much that will be. If not possible, find out if there is free stuff offered by your university. If you have a Medical Department, there are likely times/places where one can get medical help for very cheap, because there will be medical students learning how to work with patients.
Don't eat out, instead learn to cook and learn where to buy food cheaply. Your fiance can take tips from you and do the actual shopping to help you. He can cook himself too, right?
Most of all, don't quit school for a low paying job. In the end - it is not worth it. Your student status gives you a lot of perks - cheap health insurance, discount public transportation etc. Learn how to live frugally instead. You can do it!