It could be, especially if you don't communicate with your lender, ignore letters and don't abide by any arrangements they make for you to repay the debt.
As Ethel and Gina32 say, it's really vital that you speak to your lender. A friend of mine was recently in a similar position and the building society couldn't have been more helpful. But they can't help you unless you contact them. Believe me, they're used to this sort of thing.