Welcome! ProZinc is supposed to be dosed 2 times a day, once every 12 hours. It is not long lasting enough to be given just once ever 24 hours. Here's the product information sheet:
http://www.prozinc.us/content/dam/internet/ah/prozinc/us_EN/documents/ProZinc_Product_Info.pdf
It would be very helpful if you could add a signature to give us basic info like when your cat was diagnosed, what type of insulin you are giving and what type of meter you are using. Then, the info will be available on every post you make so you do not have to repeat it. You will also want to grab a copy of the spreadsheet we use here to track test results and doses given. It is a wonderful tool for managing all of this. Here are links about those things:
http://www.felinediabetes.com/FDMB/threads/editing-your-signature-profile-and-preferences.130340/
http://www.felinediabetes.com/FDMB/threads/fdmb-spreadsheet-instructions.130337/
http://www.felinediabetes.com/FDMB/threads/understanding-the-spreadsheet-grid.156606/
6 units is a huge dose. You did not mention when your cat was diagnosed or whether you have worked up to that dose or if the vet just started you there. I am so glad you are testing so you can keep your baby safe. We will be better able to help you with dosing advice once your spreadsheet is available.
Switching to low-carb wet food is an important component of getting the diabetes under control. A lot of us here had cats who were fed dry food for their entire lives, so we feel your pain in regards to the transition, but be patient and persistent, and it will happen. If you have not been there yet, I recommend you check out catinfo.org for a crash course in feline nutrition. I have a l ink in my signature to the cat food database that comes from that site. It allows you to filter by your desired parameters, and it is very helpful in finding foods to try. The Dr who created it recommends, "start with protein minimum of 40, fat maximum of 50, carb max of 10, and for cats with kidney issues....phos less than 300." (Most of us find it necessary to go lower in the carbs. 5% or less might be a good goal.)
I get my AlphaTrak strips from Amazon. I'm a Prime member, so two day shipping is included. I always make sure I have an unopened vial of strips in addition to the open one I am using. When I finish the open one and need to start the other one, I put in my order. That way, I never risk running low. If strip cost is an issue for you, there are people here who use other types of strips with the meters (freestyle?). There are several posts here about that topic, if you care to search for them.