Congratulations on the 2nd successful poke Nancy!!!

You'll be a pro in no time! It really is about letting go of our fear and just doing it as much as anything. I'm sure your Hairy is like most of our cats...he is very "in tune" to how you feel, and if you're stressing, he knows it. Like I said last night, they are very good at using our love for them against us!!
We all really do understand how you feel..we've all been there, but as this adventure moves on, I'll bet you'll soon be telling another new mom or dad that if YOU can do it, they can too!!
It's great that your vet is also recommending additional testing...When you can do it for now! The tests that are most important are these (but for now, whatever you get is better than nothing)
The most important (for safety) are Pre-shot tests...just because insulin IS a powerful hormone and you wouldn't want to give it if Hairy is already low. It could easily lead to a very heartbreaking situation, if not the loss of your precious kitty. Lifelong seizures, blindness, and brain damage can occur if a cat goes too low..and that's if they survive. That's why we're so big on those pre-shot tests. It's only to keep you from that heartbreak!
The next important test is mid-cycle (for dosing advice). Since "most" cats nadir is between +5 and +8 of each cycle, that's an important test because it'll tell you how low Hairy is going. Lantus doesn't work immediately (like you have a headache, take an aspirin and 20 mins later you feel better)...it takes several hours to fully kick in and then continues to drop the blood sugar for several more hours....then starts to wear off some. That's why it's given every 12 hours.....there's a "curve" using lantus....generally PS is a higher number, nadir is the lowest number and then PS is higher again.
Once you're more comfortable with testing (well, once Hairy is more comfortable), if you could get just 4 tests per day, you'd be on your way to getting some real control over his diabetes as well as keeping him safe.
As you can, try to get those Pre-shot tests, then feed/shoot. Try not to feed for at least 2 hours prior to those Pre-shot tests since it would bring his numbers up just because of the food and you don't want to shoot insulin into Hairy if the ONLY thing keeping his number up is food!
Then, IF you can, get a test between +5 and +8 ...basically the same thing your vet told you. This information will help your vet, as well as those of us here (who have a lot more experience dealing with day to day diabetic cats than most vets ever will) in determining the best dose to hopefully get Hairy into remission!! Depending on your schedule, if you can get a test at +5 to +8 at night, it's great, but if you can just get one before you go to bed, that'd be great too. Most cats go lower at night, so if you don't get a test somewhere in the night cycle, you'd be missing half the picture.....again, we just want Hairy to be safe...and you to be successful in treating his diabetes!!
As you and Hairy become more comfortable with testing, you can start getting some tests at other times...not that you necessarily need to test MORE than 4 times a day, but just some tests at different times so you can start to really see how Hairy responds. Once you learn that, you'll be able to shoot lower numbers (safely), which will give his pancreas the support it needs to heal...and maybe even start working again!!
I know you can do this! You obviously love Hairy very much, and I know you want him safe as well as controlled...that's what we all want to help you with.