Hey, I'm so sorry for what you are going through. People are right though that it's not your parts that make you a woman. You are a woman no matter what!
I can't really add too much to what has already been said. I also have to admit I wanted to say this before finishing reading the posts so I hope I'm not repeating the advice given.
Was it just a hysterectomy that is what the doctor want? Are they leaving your ovaries behind? If they are, they can still use those eggs of yours and have a serogate take on the task of the pregnancy. The baby would be completely yours and your boyfriend's baby genetically wise. The procedure is expensive though, but it's an option if you still will have your ovaries. If not, then maybe someone in your family can do artificial insemination or IUI using your bf's 'deposits' so at least half of your baby is his genetics and the baby would still be in your family.
Those are options at least. I don't know if things are that serious at this moment, but there are ways to do things to get at least part of the job done if it means getting at least a part of one of your DNA's as part of your child or children.
The only other option is adoption. You don't have to go through foster care if you really want a newborn. There are open adoptions where you and the mother and the agency can decide how much contact if any the birth mother is to make during the life of that child. But, at least it would be a newborn that you and your bf raise as your own. It's still a very personal choice and the desire for this baby can at least assist in the feeling that this is your child. In some cases, you can help the mother along and watch her during her pregnancy and her changes. There are closed adoptions with newborns as well but in that situation, you do not meet the mother and the mother looses all rights to see their child until a certain age when the child can inquire about their past after age 18 I believe. Open adoptions tend to be a little easier and sometimes faster and you still have the option of not having the mother be a part of your new child's life with you, but the mother does have the final say on who actually gets to adopt their child. In open adoptions, the mother interviews the possible parent(s) and makes their decision based on what they want for their unborn child.
I'd hate to be in your situation. I couldn't imagine how hard it must be to have to face these decisions and facts from the doctors. The feeling that something that holds such a dear future is getting taken away is so hard to face. It may not be what makes you a woman, but it is an important part of a woman's life. You are definitely not a lesser person, and nor are you not complete. I'm sure your bf will support you and love you with or without that part. Besides, it's not your 'part' he fell for, it's you!