Good morning! It looks like our resident experts found you and have been busy without me. (Which is all good, because they know way more than I do!!!)
First - JanetNJ found you! It was her video that I saw, and used as a reference on how to do it. So scroll back up and look for the little blue link in her signature - it will take you to her excellent video.
I too had a rough time trusting my vet when we were diagnosed. (Mine was mostly due to price gouging, and what I felt was sub-par care - which may have also been an expectation due to cost...) The people here confirmed my concerns with stories of their experiences. Gut instinct is something I've learned to trust over the years. So, I too worked on getting a second opinion on my kitty. It took me a month to find the right one to fit our needs. In the interim I read all I could here, and asked a lot of annoying questions. (And those experts here... I'll be eternally greatful for their patience while I am learning.) Funny part is, I am/was rather resistant at every turn. Lol. First, I was told I should get my spreadsheet going. I had decided, there must be an app that I can use that has more bells and whistles and is just better... so I tried several apps... lol. None did what I felt I needed, so I gave the spreadsheet a try. It really is the best tracking... so it gave me more confidence in the people here who live and breathe feline diabetes. When I had some information compiled I asked for a review and was told to lower Fabby's insulin. I didn't understand why, and why so quickly. I'm not sure a person can be adequately told the "why" when they don't have the experience... so I did lower, but it took me a bit of time to come around. As per my experience, JanetNJ was right again! The lowered dose is more optimal for my cat. So, I write all of this to let you know... your hesitance is normal. You shouldn't go around blindly trusting strangers on the internet. (This is true for all of the internet.) but you can jump in on this site with both feet and ask a lot of questions and read other people's threads and build that trust to gather those here you would consider experts. Then balance this advice with your vet advice (or your 2nd opinion vet) and learn how to best care for your kitty.
You got this!
Side note:
@JanetNJ I talk a lot about your video because it helped me so much. Should I tag you every time I'm trying to get a new person to find your video, or is that super annoying? How would you prefer I send people to your video?