Led L always on and arduino overheating

Hey, I have an Arduino Uno R3 since almost one year now, the problem is that suddenly it stoped working and now when i turn it on the L led is always on, if i press the reset button it happens nothing, if I upload an sketch to it it appears to be correctly uploaded but it does nothing, the most worring part it that while the arduino is on it starts to overheat. Can someone help me with this problem? (sorry for my english, please ask me if you can't understand something)