Well all the triggers seem to be there for MLC, so it would be useful to list the symptoms.
Tell us more about your situation, How old are you, how long have you been together, Children involved etc.
In the mean time there is a wealth of information in the Resources Thread, take time to read.
We are all here to support, especialy when you have specific issues.
Unfortunatly, in my experience, if it is MLC, and he is preparing the house for resale, then nothing will stop the train.
You can only detach, and wait for the repercussions of his actions.
In the meantime, look after yourself financialy. Open your own bank account and start building a nest egg. Protect yourself and offspring (if any) first, before you try and help him. Same advice as for the oxygen masks on planes. Yourself first, before other.