You need to have a folder some were on your computer even if its on your desk top. Your map files that work need to go in it after every time to you do a successful compile. The next time you do a successful compile you replace them with the latest ones. That way you can not go wrong if it goes tits up you just replace every thing with the good files out of your folder.
You know this all most makes me want to fire up Radiant and steal the thing of you. If I had a drop box you could put the files in I would be tempted to steal them and have a look.
You do seem to be having some problems but like I said before a mappers life is a lonely one when things go wrong. But eventually they can be sorted you just need to know when is the right time to press the stop button and go do some thing else. It will all ways be there when you are ready to come back to it and believe me you will come back to it. Mapping is a disease once you catch this disease its with you for life.
There is no rehab for mappers you just have to close your eyes take a deep breath walk into the middle of the garden/yard look up at the sky fill your lungs and in your loudest voice shout out for all to hear ARGGHHHHHHHHHHHHHHHHHHHHHHHHH as I said before it scares the shit out of the neighbors and local wild life but it makes you feel so much better. Now admit it you are reading this and you are feeling better all ready. Look up at the ceiling close your eyes think Arghhhhh. Lean back in your chair think Argghhhhhhhhhhh. Lean further back in your chair think Arrggghhhhhh by now you should be on your arse on the floor scrambling to get back into your chair. Now if you had kept your eyes closed in the first place like I told you you would feel so much better and would not be scrabbling around the floor like a crab and your computer desk would still be in the same place you left it instead of looking like a fooking bomb site. As it is your desk is in disarray you have crashed to the floor and her in doors is going to burst in at any moment and punch the shit out of you. It sort of takes the edge of your mapping problems I guess.