What helps B12 deficiency other than injections. Can't take pill form.

I was told 10 yrs ago I had a B12 deficiency, my then doctor was wonderful, and I went for 1 shot a month for 1 year. I am once again severely B12 Deficient (blood test confirmed) and only after 2 shots (1,000mcg) my new doctor said I no longer need them and to take B-complex vitamins. I was told by my previous doctor that some people just don't absorb the vitamin and they make me extremely nauseous and I get bad stomach cramps. I definitely feel the decrease in energy and know I need B12 somehow. Any suggestions as to what kind is the easiest on the stomach and will I definitely absorb them into my body. I thought that was the reason for the injections. Any suggestions/advice would be greatly appreciated. Thank you.