Charlene, I don't know much about DSWD's procedure, but logic tells me that they should not send your kids for adoption unless you and Kevin are found guilty. To have your children under their custody is ofcourse different. It is so sad specially that there are kids involved.
The Embassy, as I said on my previous post, is surely overseeing your case. You may not know it, but they could be there at the background. The Embassy is a separate entity, and just outside is the Philippines with its governing laws.
Have you given the embassy enough details, ie. contact details of Kevin's family in the UK? They may be able to support you emotionally and financially for the time being?