Hi Erica, let's see if we can address some of the prolapse issues. Vaginal childbirth is the leading cause of POP, there is so much potential for damage to occur to structural tissues. The good news is that your uterine prolapse has been recognized already so it can be addressed.
First up, you truly should try to see a urogynecologist if possible, this specialist addresses any and all POP issues and should be able to not only correctly diagnose the degree of prolapse, but also advise you about the types of non-surgical and surgical treatment options as well as moniter the symptoms.
Women with POP often experience back, pelvic, rectal, and/or vaginal pain so this symptom by itself is extremely common. It is of concern that you have such intense pain at this point after delivery; another reason to see a urogynecologist. It is quite likely that once you see this specialist, you can be given some treatment options that should help ease the pain and discomfort.
Another big concern to me is that women with new babies that also have POP issues going on don't realize that every time they pick up their babies, it puts downward pressure on their pelvic region which will aggrevate the POP issues (and in your case make the pain worse). I realize that it is nearly impossible for a new mom to not pick up her baby and although I recommend that all women contract their pc muscle prior to picking up their babies, so soon after delivery it is often extremely difficult to contract the pc muscle. Once you see a urogyn, he/she can advise you about whether or not you can utilize some kind of support garment if you are alone during the day and are the only one who can pick up your baby (ideally, someone handing the baby to you while you are already sitting down would be much better). Once you are healed up enough from your delivery, there will be a few different treatment options that you can utilize.
If you have difficulty finding a urogynecologist in your area, send me a PM and I'll see if I can help you locate one.
Good luck, I hope your pain levels off soon!