my suggestion is that if what you are doing now is not working for you, then do something different.
i too lost a lot of weight, way too much, when i did the raw veggie thing. i also had muscle cramps and deep fatigue. and yes, my diet was exceptional, i was getting plenty of protein, taking B12, etc. Things only got better when i started eating meat again.
if nothing else at least get a high quality form of B12 (methalcobalamin) and take that along with a complete B multi.