I'm Doug, and I'm very sorry to hear of your situation. My goal is to provide you with excellent service today.
This seems like a very crucial matter for you, and the complexity of your situation---with a disabled child and a prenuptial agreement---- suggest that an in-depth conversation might best suit your needs, and my ability to assist you. If you are interested, for a very nominal charge I can offer you a personal phone conference as opposed to continuing in this question and answer thread which is searchable and viewable by the public.
Let me know if you don't want a call and I will be happy continue here with an answer for you.
Either way, whether I call you or not, in order to give you a clear and concise answer, I will need some additional information about the circumstances, please.
1. You are about to use your retirement account---which per the pre-nup is your personal property?
2. How may children do you have?
3. Is your husband capable of working if he chooses to? What kind of income is he qualified to earn?
4. What specifically about the pre-nup are you wanting to contest?
5. What is the alimony restriction set out in the pre-nup
Thanks in advance,