radio turns on and off by its self and now does not work at all
And your question is?
Clearly your radio is broken and requires replacement.
Check all related fuses. You may get lucky.
I agree with @NYBo, make sure you have good power getting to the radio before saying the radio itself is bad. Since the unit is now totally dead it makes things pretty easy to figure out where the problem is really at. If the radio truly is at fault you have a couple of options. You can replace it with a new or used unit. Ebay is a good place to find them at a reasonable price. There are also places that you can have your unit repaired. Here is one place that is great to deal with. They can also sell you a replacement unit if you want to go that route. There are other place like this also. They can also make mods to the unit, like add an AUX input jack or add Bluetooth to the radio.
If you decide on replacing the radio be very carful which replacement model you choose. Some units have different options that may not work with your model car. Things like remote control. The folks at 1 Factory Radio can help you with that.