How are you feeling worse?
If you've just started the Prozac within the past few weeks you may experience side effects such as nausea, headache, dizziness, diarrhea, etc. It can also affect you emotionally causing depression and/or new or increased anxiety.
These side effects generally subside over a couple of weeks so if it's been longer or if you really feel bad let your doctor know.
Depending on what your side effects are they can usually be managed, sometimes even with OTC remedies. Talk with your doctor or pharmacist.
Best regards and I hope you feel better quickly.