Hi notsure and welcome to the forum
I guess your question is therefore how do I deal with my debt over the next few years, rather than write it off?
Firstly, you cannot afford to continue to fund a negative cashflow of £1,500 per month, so the sooner those investment properties are placed on the market and sold the better.
Secondly, you ought to take professional advice from an insolvency practitioner as to your options, as you clearly cannot afford to service your debts on your current income. You ought to be able to keep the car, so long as you can afford to continue with the HP payments, and insolvency proceedings are unlikely to affect your fiance's property, assuming that you have developed no interest in this asset.
Regards, Melanie Giles, Insolvency Practitioner