No, a failure would be someone who got the diagnosis and had their kitty put to sleep, or who got the diagnosis and just started blindly shooting insulin without testing. You, my dear, are no failure.
The neuropathy is a scary looking symptom but fairly common. You can probably find the Methyl B12 in a local health food store if you don't want to wait. It helps, but getting the numbers into lower ranges is also part of fixing it.
Yes, those three are the ones we recommend. They all last longer than N, and have flatter, milder cycles. There are protocols for them on the Lantus and ProZinc forums in the forms of topics on the top of those forums. Levemir acts very similar to Lantus so the info for it is on the Lantus forum.