Hormonal imbalance, like low estrogen levels and drop in testosterone levels, thyroid hormones disbalance, are related with decreased libido in women.
It is well known that estrogen is important for the normal health of vaginal tissues and interest in sex.
Before, asking for contraceptive pills, that will eventually ease your symptoms, you should visit your physician or gyn, for addressing an underlying medical condition or medication that's known to have sexual side effects.
All types if birth control pills are associated with low libido as a side effect, and they may cause permanent changes even after stopping their use.
Many women find that triphasic birth control pills (ones that deliver differing amounts of hormones every week) interfere much less with their sex drive than monophasic pills (which deliver the same amount of hormones each dose).
In your case, probably, it will be much more appropriate to take estrogen therapy for vaginal dryness (vaginal dryness leads to painful intercourse, interfering with ability to rich orgasm, all of these resulting in low sexual desire), that may also affect the size of your breasts, along with non-hormonal contraception, like condom or diaphragm.

Visit your gyn!