I've had clinical depression for 20 years and been on ADs for nearly that long, and like other meds, you do need to go in periodically and have them adjusted. You don't say how long you've been feeling down, or your dosage of Prozac. If you haven't increased the dosage in many years, a simple increase in dosage is sometimes all that's needed.
I've been on Prozac, Zoloft, Paxil. Currently I'm on 450 mg of Effexor and 150 mg of Zoloft daily. My thyroid quit working recently which effected my depression and (with my Phych's ok) I took an extra 50 mg of Zoloft for about 2 weeks till the thyroid meds kicked in. (Low thyroid can cause depression, too, as it helps regulate hormones-especially in women.)
As for a situation that you are unable to deal with on your own, you might try counseling. I've been in counseling three times, and each time it made a big difference!
Please call your doc and get evaluated!

Depression is a very serious illness!