|My cmoy is a total failure and I dont know what's wrong with it there is sound but very muffled
By "muffled" do you mean that, with studio music you can hear only the ambience -- the echoes of the sound bouncing off the walls and back to the mics, but not the sound going directly from the acoustic instruments and voices into the mics? If that's it, you probably have a ground fault -- you're getting phase cancellations, leaving only the ambience. If the amp sounds okay for a bit after applying power before going muffled, your ground fault is through a high resistance. Otherwise, you have a 0-ohm (or near-to) ground fault.
Here's what you need to check: first, if you have a metal case, check the resistance between your signal ground and the case; it should be infinite, unless you've chosen to tie your signal ground to case ground. You should only do that step once the amp is working and you can hear some ground loop hum, perhaps when touching a switch on the amp.
Second, check for ground faults within your input and output jacks. Careless soldering can often melt the plastic keeping the metal parts from touching inside the jacks. You may need to desolder the jacks to test them, so that you're not incidentally testing paths through the circuit from one channel back to the ground, leading you to falsely believe you have a ground fault.
Failing that, disconnect any grounded components one by one, starting with the headphone output. (Obviously this doesn't apply to the power or signal circuit resistors!) This makes testing harder, of course. In the case of the input and output jacks, you have to use aligator jumpers to hook your source or your headphones into the circuit. For headphones the plug tip is the left channel, the "ring" in the middle is the right channel, and the "sleeve" going the rest of the length down the plug is the ground. (You occasionally see these type of plugs called TRS plugs -- tip-ring-sleeve.)
In general, simplify, simplify, simplify. This is why I recommend building a cmoy amp in testable sections: build the power supply, test it, build the basic signal circuit with no jacks, switch, or pot in the circuit, test that with a volume-controlled source, then add an input jack and test it, then add the output jack and test, then add the pot and test with a line-level source, and finally add the power and (if needed) crossover switches and test yet some more. This ensures that if you break something, you definitely know what you didn't
Don't give up. I have faith that you will be able to fix it. I have built four of these, and only one so far has been built without much trouble. The other three had ground faults of various flavors, each taking a few hours to a day to chase down and squish. Fortunately, this circuit seems relatively forgiving of hookup problems: I haven't yet killed a component, aside from one cheap headpone jack I fatally melted with my iron. In all other cases, I eventually got the circuit working with the original parts.
These problems are frustrating, labor intensive and demoralizing, but beatable. You can do it.