Body temperature keeps dropping -Low B12

Hello all. I came across this forum whilst researching B12 deficiency. Here's our story. My partner (45 with two kids) had a haemorrhage when she was 18, they operated and she has been on phenytoin since without any real problems, but well overdue for getting rid of phenytoin anyway which we are trying, but as she reduced the tablets she started getting numbness/strange feelings etc so went back to normal dose (under an endodoctor) This year her body temperature started to drop to below 36c, where she would get very cold, and sometimes shivers. We cant seem to find out why it keeps dropping, but is definitely worse during stressful situations. She had scans etc and her adrenal glands (the nobbly bit on top) was quite small, so the doctor thought maybe this was the problem and started her on Corticosteroids......this all happened over 6 months or so, all the time her immune system was at zero, and she would come out, catch something and end up back in, so we're not sure we are on the right track, but with her system this low the stats could mean many things. Anyway I have frantically been searching the net and came across B12 deficiency problems ( we are both veggies but eat good foods) it turns out in addiction to problems with being veggie, the phenytoin also knocks B12 for six. Eventually managed to get the doc to properly check her B12 levels (not just the ordinary blood test) this reveals her B12 levels are low at 120, so at last we have something real to look for. It may or may not be the cause of her problems, but it's something to go on at least. Doc has put her on injections for the last week but the levels had only gone up to 135, he has now doubled the dose for another  3 or 4 days, aiming for 200. She had a stressful situation last week and her temp dropped again, but she is now around 36.4 again. In the last 6 or 7 months she has been in isolation hospital for about 5 months in all, on and off, up to 6 weeks at a time. She picks up, goes home and then catches something else that knocks her for six. Then back into hospital for another few weeks. This time it was a severe asthma attack.

What do you think, sound familiar to anyone?