The pill can have a MAJOR effect on mood and libido! I was on Nuvra-Ring for a year, and towards the end i had some major issues with sex, with my body, with just about everything! I thought i was going CRAZY! then, i talked about it with my husband, and we traced me feeling wierd back to be being on birth control. so, i went off of birth control, and it made me feel like a TOTALLY DIFFERENT PERSON!
that said, realize that this isn't the end of the world. a lot of people have said that no sex kills a relationship, but if you and your wife really love each other and really care about keeping your relationship happy and healthy, you'll work things out. my theory, and this is hypothetical, is that somehow her strict religious upbringing is kicking in (either conciously or subconciously) since you've been married. to her, perhaps married couples only have sex in order to procreate, or don't have sex that often. please, sit down with your wife, tell her how much you love her and how much you want to be a good husband, and explain to her that you want to make your marriage be all it can be. do some research online about birth control affecting mood and libido, and suggest that perhaps she go off of it for a while (it's a good idea to skip a month or two after a year of taking it so your hormones can self-regulate). tell her this not because you want to have sex with her (you do, but talking about it at this point will only upset her), but because you're worried about her and her state of mind. then suggest that you go to a marriage counselor, not because you want to pressure her into sex, but because you want to make sure that you're both doing all you can to build a sound, happy foundation for the rest of your life. if divorce is not an option for you, you BOTH need to do all you can in order to keep your relationship alive and fun. also, i would suggest dropping the sex thing entirely until she gets off of birth control/ you go to see a counselor. she might be resistant to change at first, but if you sit down and tell her just how you feel about things (not about sex!), and that you want to do everything you can to make it right, she'll probably realize that it's important to be happy!
another thing, what were her parents like? what kind of model for marriage did she have as a child? did her parents ever tell her that sex was bad/for procreation only/wasn't important? oftentimes the only model for behavior we have comes from our parents, and when something is going on that we don't understand, we often revert back to what they taught us. these are things that could/probably will be asked in counseling. i hypothesise that much of this has to do with her hormones due to birth control and her background. was she on birth control at all ever for any reason before you got married? because if she wasn't, i'd be willing to bet money on the birth control causing the libido issues. ESPECIALLY since you said she had a healthy libido beforehand. i know- i've been there!
realize that you can go to a christian counselor, who will help you both with your marriage from the perspective of religion. this counselor might help her to understand her body and her sexuality from a context of religion, which would appeal to her puritinacial upbringing. if you are both attending church, ask your pastor after service about what the best options open to you both are.
your wife needs you right now, because she's probably feeling down on herself because of this whole sex thing. I felt HORRIBLE when i didn't have a libido, because i knew what it was doing to my husband, and i thought i couldn't change (you said your wife said almost the same thing- that she felt she couldn't change). love her every way you can- make sure she knows that she's special/beautiful/wonderful and that this sex thing is just a minor blip on an otherwise fun and happy marriage. sit with her, talk to her, tell her that IT'S NOT HER, that it could be the birth control, and that she can change, and that you're there for her while she's going through this. she needs massive amounts of support from you right now! make sure you're making time for both of you- even though you're not having sex right now, you still need to be going on dates and making time for just the two of you. give her a massage, take a bath together, go have a picnic- and assure her that sex is not going to be the result. if she feels pressured, she's just going to feel worse about herself. MAKE SURE that your marriage is being cultivated even though you aren't having sex. be intimate in other ways. perhaps, AFTER you've had the birth control/counseling discussion, and AFTER you have made it CLEAR IN EVERY WAY that you're not going to pressure her for sex, you can ask if it would be ok for you to masturbate with her- have her hold you while you masturbate. this way, you are having orgasms, she's participating but not feeling threatened, and you both are being drawn closer. but i would say leave this question until AFTER the birth control/counseling/ long talk/ massage/ etc.
I commend you for caring about your wife so much! It's a wonderful thing that you are doing for her, and just be patient! I have been in her situation before- if you'd like to chat about it, feel free to PM me or AIM me, and i'll help you try and understand what it's like from the woman's perspective as much as i can!
GET THAT WOMAN OFF OF BIRTH CONTROL PRONTO!!!