Hiya, Wow thats alot of oweing, but hey we all been there!!!
Firstly yes you can have an IVA and a mortgage, business etc whereas with bankrupcy they take the lot.
However there is also some serious downsides to an IVA, like the company who sets it up and runs it for you can charge you thousands, your credit scoring is absolutely shot at etc etc.
do you use one of the bank accounts listed above for your business or is it seperate? and if so is that one also in the red?
Have you approached your lenders and explained the situation? sometimes they can be more understanding than you think.
You said your name is on your sisters mortgage, are you the 2nd name or guarantor?
The citizens advise are excellent with situations like these, if you take along statements etc of everything you owe, bank accounts etc alot of the time they will do draft letters for you to send to your creditors offering them set amount of money each month that you can afford to pay as they do you a budget.
I hope this helps as I found you need all the help and advice you can get at times like these.
Regards,
Paula.