You rant away, Gary! Wouldn't be the first one here to do so.
First up, let me say how pleased and relieved I am to hear that Tom has got his appetite back! That is such great news, and I'm sure that you must be feeling a lot better too as a result.
Some vets are progressive about home testing, others are positively hostile towards it. A good question to ask them is whether they would advocate giving a young child insulin without testing the child's blood glucose or having some idea of how much their insulin dose might lower their blood glucose.
Also, testing at home removes the risk of 'vet stress' influencing blood glucose levels. When cats get anxious travelling or during the surgery visit it really can send their BG levels soaring. It isn't, therefore, the most reliable data upon which to base dosing decisions. Doing curves at home also saves a lot of money. We're lucky with our vets. Our main vet reviews Saoirse's spreadsheet online and he prefers not to bring cats in to the surgery unless absolutely necessary because it is better for them not to be subjected to unnecessary stress.
I can really relate to your frustration at being talked down to by your vet. I've been through similar experiences with vets at other practices than the one we're registered with now. I have severe PTSD, panic, agoraphobia, and OCD. I don't venture out unless it is something life-threatening for my Saoirse. I get very, very anxious at the vets (not helped by worry about my girl) and I also have terrible problems with pressured speech. The mouth works OK but what comes out of it at times is very jumbled. When I first took Saoirse for a consult when she started drinking too much and pulling fur out of her side the vet just wouldn't listen to me properly (even though I explained that anxiety made it very difficult for me to communicate). She refused to run any diagnostic tests and dismissed all of my observations about Saoirse's obviously poor clinical signs as being "completely normal" for "an old lady." I was just dismissed. I felt that she just treated me like a hysterical cat mama, and that because I was so anxious she gave no proper consideration to my valid concerns about Saoirse's poor health. I was so frustrated and angry!!! I went back to them a couple of weeks later, this time armed with a page of data showing that Saoirse was drinking more and more every day, and also a journal of observations of her appearance and behaviours. I
demanded tests, in spite of being really scared; my girl needed me to help her. Saoirse was given the preliminary diagnosis of diabetes before the end of the day. It should not be this hard to get veterinary support!!!
I wanted to home test and asked the diagnosing vet to recommend a meter. She refused point blank to give me any advice. I was scared for Saoirse and so angry and upset that I couldn't get proper support. That's when I joined FDMB. So glad I did. It has helped me to become a lot more confident in my dealings with vets because I can sound things out here first.
The good news is that we're now with a practice nearer our home. They're really quite switched on about diabetes (even run a special diabetes clinic). I share Saoirse's spreadsheet with our vets. They can see from that how careful I am with her. They know that I will discuss all her treatments and her testing. Sometimes they may not completely agree with some of my choices. In particular, it took them a while to stop raising a wary eyebrow about my choice to monitor her BG levels so closely. However once we had been at the practice for a little time and Saoirse started improving they seemed less concerned. Now I just get on with it and we just don't mention the matter.
One thing I really like about our main treating vet is that he is open to discussing things with me instead of dictating what I should do; and he'll research things I'm interested in trying, too. If I find a treatment I think might help Saoirse we review the pros and cons together and then I make my decision about whether or not to go ahead with it. I think over the last year we have built up a trusting, successful relationship. We are partners in Saoirse's care, and it makes the world of difference. I know that you really like your current vets. Once get one of our spreadsheets going for Tom and get your test results into it, you'll be able to show your vets the and it will prove that you know what you're at. (One of the members here can help you set up the spreadsheet. Just let us know when you're ready.
) Hopefully if you can get past the 'diabetes teething stage' with them you might be able to create a good partnership with them to get the best results for Tom, as I've managed to do with our vets for Saoirse? I hope so.
One final note about vets. It is vital to have good cover and support from whichever vet you choose to help Tom with his diabetes. There's no running away from the fact that diabetes brings certain risks and potential health complications such as hypoglycaemic episodes or problems with ketones (can lead to diabetic ketoacidosis - DKA- a potentially life-threatening complication of diabetes). A good out-of-hours service is very important, whether it be that you need to get advice about Tom out of hours or whether he may need to visit the surgery out of hours to receive emergency treatment. Check your transport options for emergencies, too. It is also vital that you discuss any additional treatments you wish to give to Tom, including any dietary supplements. As you learn more about how to treat Tom's diabetes and you've learned to work with his insulin, you'll probably find that once your vets are confident that you know what you're at you'll be able to manage the diabetes with minimal veterinary intervention (usually just routine reviews of how well-regulated Tom is).
Sorry for rambling. PTSD's really bad at the moment and I'm not able to edit myself. Be sure to give your little furry family lots of scritches from me. And here are a few
for you.
Mogs
.
Keeping fingers and paws crossed he keeps that up. When you can get a decent bit of grub into them it can break the cycle and they gradually start eating better. 
But at least I was building my confidence. That's the important thing, not just for you, Gary but because Tom will "read" you, as you know! As the actual testing progressed, I modified things as it became necessary ( you will too!) and do it completely different now.