My doctor told me it takes a while to actually start to be effective. You don't really notice a change until at least week 5 and theres really no marked improvement until 3 months. I understand the frustration. Please hang in there. It just take a little time for your body to adapt. Hopefully this gives you the relief you need

It will take a few months to fully work. I have been on b12 injections once a month for several years & they help me quite a bit