Spook - little consolation but this is history repeating itself (what you're going through and what I did). But with us it wasn't St. Tropez, it was Camber Sands! Big big hug from me, I know what it's like pet!
Are you up to checking your finances? I know I keep harping on about it but is he making sure you've got enough in your purse. Do you have a joint account? Is he making sure that the service bills are being paid ... and the mortgage if you have one. I'm saying this because he's now having to pay for the flat and you mentioned that the business is in trouble. If the business goes belly-up, then being the selfish sod he is (hope you don't mind me saying that) he'll probably look after his own roof primarily.
You say you don't work. You are at this stage eligable for Income Support BUT once the DWP get involved, he will be assessed in due course for CSA. It is almost impossible to overturn a CSA decision once it's made, so you may get a better deal if they're not involved i.e. an agreement met between yourselves.
I'm telling you all this because if history is repeating itself, this will be the next episode. My ex assured me when he went to find his space that I would be OK putting all the food bills on VISA for him to pay. But when he found he had his own bills to pay (and she was chewing his ear with verbal support), he starting disputing the bills and I ended up having to pay VISA from a block payment he gave for the rest of the housekeeping which was needed to pay gas, leccy etc. I certainly had to tighten my belt. I did end up at the DWP and that day was very, very hard.
I hope this isn't too hard advice because I know you're still very upset at his absence. I just don't want you to incur debts which will stress you out even more.