How to protect my 12 V, 10 A circuit? I am using a fuse but it failed
A thermal breaker or "normal" fuse is not very good protection for a switching power supply.  They can take tens or hundreds of milliseconds to react, but the power supply components can be damaged in microseconds.

Linear Technology makes several input protection controller chips that include drive for an electronic circuit breaker that can respond in microseconds, overvoltage and undervoltage shutdown, and reverse polarity protection.  I've used them in MIL projects with very harsh electrical environments and transients.