You need to talk to a lawyer if you have not yet. Get as much done by W lawyer after you both talk about it then you take it to yours and go from there. At that point it should be close to a proper document
Me late 30's W mid 30's T 15, M 10 S4, S7 ILYBNILWY June 2015 In house S July 2015 W rings off Oct 2015 My ring off Feb 2015 Separate houses June 2016