I do feel there is a degree of MN double standards on this thread - if this had been written by a man who had married his GF and then refused to allow her and her children to move into his house as agreed - instead expecting her to remain in accomodation unsuitable for her and the DCs - he'd have been soundly, and rightful, condemned.
Surely no one expects the OPs DH to stick around as a "live out" husband (in a one bed flat with several DCs) while she decides whether she's willing to give up the single, independent lifestyle she values? A man would be told in no uncertain terms that he is being unreasonable, and emotionally manipulative, and that his DW is better off without him.
I agree that it would be catastrophic for the households to merge while the OP feels the way she does - but it's not reasonable to expect her husband to wait around until she decides if she's ready to fulfil the commitment she has made to him.
I think the honourable thing for the OP to do is end the relationship, legally separate and divorce at the earliest opportunity - with the OP covering all legal fees.
OP Your hasty decision to marry earlier this year could be very costly. You have, irrespective of any pre-nups that were signed, changed the legal status of your relationship with your DH. You are no longer two single people in a relationship, you are a married couple, with two marital homes. The law is applied on the premise that married couples cohabit, and share assets. Your DH has rights regarding your assets and property, as you do his. These rights may, or may not, be limited by a pre-nup, but in any event, the existence of such a document will require court interpretation and ruling - that's the whole point, isn't it?
Your refusal to live together as a conventional married couple gives your DH grounds for divorce. As you have more assets to protect than him, I imagine your legal fees will be far higher than his; and you may find that a court orders you to pay his costs as well.