I went on my two week vacation from work and came back to discover I have to get a hysterectomy and will have?

to take off 6-8 weeks, since I already have used up vacation time and may have one week of sick time aculations, what does a person do? how can one get operated on and then have no money? after being in the company for 7 yrs, can they fire me or not pay me or can I apply for unemployment?