Hi Gracie's Mom!
I just wanted to welcome you to FDMB, although I'm sorry you have to be here. You've come to a great place for help, though. The wonderful people here helped me get Jersey into remission after just a few months. We were Lantus users, so I'm not very familiar with the Prozinc you've been using. There are lots of experienced users here who can help you with it, though.
Definitely don't buy an expensive test kit from your vet's office. My vet actually never mentioned home testing. I only started doing it after I found FDMB. Thank goodness I did test at home. Otherwise, I would have given Jersey too much insulin, and she might not be with me today. I simply went to Wal-Mart and bought a ReliOn meter - I used the ReliOn Micro. I think the meter cost me about $15. You'll also need to pick up the lancets, which are the needles that you will use to poke the ear with. Since I actually tested on Jersey's paw (I couldn't get the hang of ear testing), I bought the bigger lancets. I think a box of 100 lancets cost $5 or $6. You'll also need to buy the test strips to go with the meter. Those are the most expensive "piece" for home testing.
The first vet, the one who diagnosed Jersey, wasn't very knowledgeable about feline diabetes. He prescribed an insulin that wasn't very good for cats, pushed prescription dry food (that was high-carb), and didn't mention/encourage home testing. We went to a second vet, who prescribed Lantus for us, but he still wasn't very knowledgeable about dosing. So....after we got our insulin prescription, we actually never went back to either vet. We followed the advice of very experienced users here. They were able to tell us when to increase the dose, decrease the dose, etc. The vets wanted us to come back in for glucose curves and fructosamine tests. Since we were testing at home, though, we didn't need those tests. We already knew exactly what Jersey's numbers were. That saved us a ton of money in the end. Of course, we were also fortunate that Jersey didn't have any other health issues going on that would have required vet visits.
Anyway....hope this helps!
Shelly