I've been on cyano b12 sublinguals for 3 weeks then I stopped that, and I've since had 4 x weekly injections of hydro b12, and for the past 4 days I've been taking 500 mcg of methyl sublingual b12 tablets.

But I feel like my tingling and balance problems have gone away, but it's brought on new problems like panic attacks, nausea, loss of appetite. On warm nights (I live in Australia), I feel a headache and disorientation coming on, then I get weird thoughts, can't sleep and just feel paranoid. It's only been happening since taking B12. It only happens in the evening and at night.

Is this normal? Should I continue taking B12? I feel so scared.

Also, I meant to be getting my flu injection tomorrow, and b12 shot, but don't know if I should get both, one, or none of those injections...

500mcg of B12 is not very much orally.
Very little of that is absorbed, compared to your injections.

There is a connection with mental symptoms that does not
happen to everyone...
It is discussed here:
http://www.alternativementalhealth.c...s/pfeiffer.htm
It is controversial, but may happen rarely.

Are you taking methylfolate too? You might add that in 800mcg a day. They both work together and if you are not methylating due to DNA errors, you'd be missing the activated methylfolate.
It is called Metafolin by Solgar.

Rose, who used to post here, used to say there were ups and downs with replenishing B12. She was severely ill with low B12 and finally was diagnosed.

When do you take the B12? In the morning? By night it would probably be gone from your blood and into the tissues.

This study:
http://www.ncbi.nlm.nih.gov/pmc/arti...able/T1/#TF1-4
found that 500mcg orally led to 9mcg absorption.
Compared to an injection which gives 150mcg from a 1000mcg injection.
You can see a significant difference there.

I think it can be very difficult to figure what is going on. It could even be do to other medications you are taking.
My Lisinopril which I took at night, woke me up 2-3 hrs later with swelling and burning! (blood pressure medication). Some nights I'd sleep thru and some were a nightmare. (heart pounding was the worst).

It's important to keep in mind that correlation does not imply causation, or in other words, the new symptoms might not be related to the B12.

There could be other things playing. Sure, it is possible that you have an averse reaction to B12, but the chances are very very slim. If there is a relation, it might be that your body is readjusting to the availability of the vitamin, which can cause discomfort.

I've seen it established numerous times that people feel a bit worse when the B12 is kicking in before feeling better. ("initial worsening") I've also seen a lot of people getting stressed out by the injections.

Also, don't forget that even a hydroxocobalamin dose that is 10,000 times higher than what you are taken has been proven to not have dangerous side effects. (Obviously, don't try this at home!).

If you keep feeling worse, you might want to see if the reaction goes away if you stop taking B12. Needless to say I'm not a doc, and if things feel very wrong - you'll be the best judge of that - don't hesitate to contact a real one.