Try contacting Bankruptcy help forum uk as they might be able to put you in touch with help in Spain.
They also have a forum which you may be able to get advice from other people going through it, who’ve had property in Spain.
There are other sites out there but this one really helped my friend who was living in Spain at the time, hope they can help you. She has now returned to England with nothing, but now has no more hassle and is a lot happier, so please don’t get too down about it. Try and get as much info and know your legal rights here in Spain. I don’t think Banks want to repossess and its a last resort, so maybe you can still do something about it. best wishes, Ruth