Don't feel like an idiot. Heck, when Hidey was first diagnosed I was TOLD he was given Prozinc, I was CHARGED for Prozinc, and after about 2 weeks of crazy high numbers I realized it was VETSULIN!
We trust our vets, just like drs BUT they do not have all the answers and every case is different. I will not knock vets because they're still human lol and I truly do think their intentions are good.
I think the whole situation is just like humans. A dr can prescribe you something they think is right only you and your body know if the medication is right for you or if the dosage is too high or too low. It might have worked for someone else but not you. Its all trial and error.
Anyways, my point being dont be discouraged with your vet BUT listen to your gut as well. I hope you have a vet that will listen to your opinion as well.....unfortunately mine is not, and gave me this "who do you think you are" look....even after I took Hidey in with all his bg readings and in REMISSION! Oh, well lol.
Have you popped in the Lantus group? You may want to start lower and work your way up. 1.5 still seems a bit high, hopefully someone with more dosing advice on Lantus will pop in.
Also, GREAT job with monitoring those LOW numbers this morning ;-)