Hi Rainbow
In bankruptcy your beneficial interest would be caluclated by taking the current value, and deducting the prior charges. So this leaves you with equity of £12,000, which would be divided equally between you and the co-owner - therefore £6,000 each. You would have one year to raise the money from friends or relatives, to avoid possession proceedings being taken against you. In the meantime, so long as you kept paying the mortgage and secure loan, there should not be a problem in you remaining in the property.
Hope it doesn't come to this for you!
Regards, Melanie Giles, Insolvency Practitioner for over 20 years.
For further details contact me at
http://www.melaniegiles.com and view my IVA blog at:
http://melaniegiles.blogs.iva.co.uk