B-Right by Jarrow has a nice formula.

http://www.iherb.com/Jarrow-Formulas...eggie-Caps/110

It has a modest formula with not too high levels of B6, and has activated folate, B6 and B12 in it. Of course the B12 is not really high enough for intense treatment.
You don't have to take this every day...you can do every other day or twice a week, to start, if the B6 worries you.

Many people over the years who have posted here have used it, with success. I believe it is available online at other places too, and perhaps Amazon now.

Those compounded injections, may not have a preservative in them, and in that case injecting them may be problematic. I'd call the compounding pharmacy up and ask. I hope you are keeping them in the refrigerator? Most of the time that storage is recommended.

What can happen with very high dose vitamin supplementation that lasts a long time, many months or years, there can be a vitamin dependency syndrome that occurs. This is one reason I don't recommend really high doses of anything.

Vit C was the first to be recognized as causing this. And I think it is possible with other vitamins. It involves the body "getting used" to very high doses, of some thing, and then over time the chemistry and enzymes, then "expect" this flood all the time. Withdrawing the vitamin then can cause deficiency symptoms. In the case of mega C dosing, trying to reduce may produce scurvy in some people.

http://orthomolecularvitamincentre.c.../dependencies/

Some dependencies may be inherited like B6 dependency in infants who have neonatal seizures, that respond to high dose B6. But cases of induced dependency also occur, for whatever reason.
http://emedicine.medscape.com/article/985667-overview

http://books.google.com/books?id=QBJ...ndency&f=false

So I think it is important for you to find a dose, that works for you and keep it steady. Flooding systems here and there may not work over the long haul. Stopping and starting high dose apparently is not working well for you.