If you owe a significant amount of debt, part of what you may have to deal with is contact from debt collectors. It is legal for creditors to attempt to collect on money owed to them, but there are limits to what they can do and tight restrictions on how they can treat debtors. The Fair Debt Collection Act protects you, and it can be in your interests to learn what this law does.
Debt collectors are often aggressive, but consumers may believe they have to tolerate this behavior because they owe a significant amount of debt. No matter how much you owe, you still have rights. The FDCA offers you protection against certain types of treatment, no matter the details of your individual situation.