Kim,
My now 2-yo DD was a reflux baby and needed constant attention and boob time. Four months is so young to be stuck with a pacifier or in a crib. Babies are desperate for the comfort and security of Mom. I KNOW it is frustrating to feel like she's on you all the time, but it's really something that will set the stage for her future development and healthy relationship attachments to you and other people.
I encourage you to get a sling or baby wrap. MamasMilk.com and KangarooKorner.com have a good selection. For starters, I'd suggest getting an unpadded ring sling. They're easily adjustable and fast to get baby in and out. This way, you can carry baby around a lot (it's really what she wants!) and still have your arms free to do things. Then she's close for frequent feeding, too. I know, I KNOW the days seem soo long right now--we dealt with thrush for 9 months in addition to DD's reflux and neediness and 16-hour nursing--but the years will fly by and you will wonder where your baby went. (I have a 12-yo, too, and I can attest to that!) With the ring sling, you can pull the tail so the baby's in really close during nursing; then you're practically hands-free. The Maya Wrap is another good one for that, just tying the baby onto you, and she can shift to the boob when she wants it.
I wore my now 12-yo for three years, and he is now a very independent boy. Um, young man. :-) I didn't wear him everyday once he was walking, but I took the sling, and when he got tired, I'd sling him. I'm still wearing the 2-yo occasionally--she's much more wanna-be-on-my-own than he was at this age, but she's still got her needy mamma's-girl moments where the sling is my arm saver!
Please also find another mom to hang out with, either in your neighborhood or in an official group. MOPS is a good place for mom support and break time from baby. (Christian Fellowship Church in Ashburn has a great one. Can you tell I go to that one? ;-) The real-face time will be excellent for you. I know it's difficult to get out of the house, but it will be soooo worth it, Kim.
Good luck.