Big hugs... I'm sorry you've joined the pelvic organ prolapse "club" (and isn't "POP" just way too cheery a term for the condition?)
There's a huge, and I do mean HUGE, thread here at mdc about POP. You can read through it here..
POP is generally considered a "quality of life" condition so treatment options (both holistic and allopathic) are going to vary based on how you, personally, are feeling and what you individually find "ok". There are a LOT of things you can do right now (and congrats on the new babe!):
--- Use gravity to your advantage and try to keep your pelvis "up"... feet up is good, but getting your bladder and other organs back into place with gravity is better. Prop your bum up on pillows in bed, avoid standing for long periods of time, rock on hands and knees or in a chest to floor/child's pose with your hips up, anything to encourage those organs back into place. Especially right now. Being just a few weeks after the birth a lot can change and you want to make this period of time count!
--- when sitting, avoid those donut pillows and use a memory foam style pillow if you need extra comfort. The foam will provide support (unlike the donut) without too much pressure.
--- homeopathic treatments like pulsatilla and arnica, herbal tonics like red raspberry leaf tea, Back flower remedies like Rock Rose and Star of Bethlehem.
--- acupressure on your own or acupuncture from a pro is another option. Spleen 6 and Kidney 3 are good general prolapse points, Stomach 36 can help you stay regular which can reduce symptoms and Urinary Bladder 60 is good for preventing UTIs (which are more common with bladder prolapse).
--- Mayan Womb masssage may help with POP in general (not just uterine prolapse). Mothering Magazine had an article (March-April 2010) on the massage in relation to fertility, and gave a DIY guide in the article. Search the mothering homepage for "mayan womb massage" and I'm sure you'll find the link if this one doesn't work (scroll down, it's right above Peggy's Kitchen).
--- Check out POP support forums like The Whole Woman, exercise routines like the Tupler Technique (the BAKS basics are free online, there are mdc threads about the technique, and you can start more or less as soon as the babe is out... her Mummy Tummy book has great ideas for pelvic floor healing too), and books like Beyond Kegels (a life saver in my bladder prolapsed world) and Ending Female Pain.
--- stay hydrated and regular by whatever means necessary. Void often and as fully as possible (void, stand up, then void again while leaning forward and pressing against the pubic bone or lifting the lower stomach area can help get more out of a saggy bladder). Aloe vera juice or prune juice can help with regularity, though I've often resorted to a short course of miralax or other over the counter laxative to make sure I avoid constipation right after birth.
And over all... just hang in there! There are schools of medical thought that wont even diagnose a "permanent" prolapse until a year postpartum, and symptoms that will resolve gradually once pregnancy hormones (and then breastfeeding hormones) are no longer playing such a large role. Prolapse is becoming one of the more commonly reported conditions in younger women, but the medical world still sees it as an end-of-life condition and some of the attitudes out there can be pretty scary. Attitudes and treatments are changing, and options are opening up all the time. It's really normal to feel let down or "broken" (I've been living with POP for 4 years now and still have bad days). Just be gentle with yourself, enjoy your baby, and remember it's going to be ok!