Hi Mala, Sorry for your pain and you sure came to the right place for help and understanding. I see you've already gotten replies from some of the best of the best on this site yet I can't help but add my 2cents. You don't really say you get depressed just down and moody ect. I'm on most of the meds your on myself plus a few more and I've found that by about 3 or 4 everyday I begin to feel very similar so I find myself taking a little nap at that time. When circumstances allow of course. When my daughter was younger I always knew it was nap time when she got a little grmpy and whiny.
With all the meds we are on and all the stress involved with our day to day living with pain it is no wonder we don't feel a little low, anxious, moody ect. Like you my mood picks up again in the early evening.
Sometimes we all need a little respite from our lives and there is nothing wrong with that. After you follow up on the other advice you've gotten here and talked to your dr. try the nap thing, it may surprise you. If your one of those people who just can't sleep during the day a half hour or more of quiet lying down and going some where else in your mind helps me also. Meditation is great if you can do it and believe in it.
I just saw my PC dr. and asked her about B12 shots for the same reasons you stated, I was told they only gave B12 shots to you if you have a deficiency (sp) and I don't so I'm sticking with the nap and quiet time, it works for me usually.
Good luck Mala and thats me out.