Firstly the car loan - what does it say at the top of the agreement - hire-purchase, conditional sale, fixed term loan or anything else?
I am afraid it is not the first time I have seen someone regretting taking out a secured loan - the glossy advertising looks great, happy families playing football and falling over scooters, and then the reality kicks in!
From the additional information you have now provided it does appear that you have more serious issues, and I would strongly recommend that you contact an insolvency practitioner to discuss things on an individual basis. There will be more than one option available to you, but it is important that you fully consider the advantages, disadvantages and implications of each one on you, your home, your children, your career and most importantly your future.
Regards, Melanie Giles, Insolvency Practitioner