So, you made your chain much shorter and now it doesn't want to shift down to the small ring? It shouldn't want to go up to the big ring instead.

Aside from the chain-shortening bit, it sounds like something's suddenly up with your front derailleur... so it won't shift down despite cable slack, right? You need to find out what's stopping it, if it isn't the cable. What about the limit screws?

What happens if you pull on the cable and work the shifter? Does the shifter work okay like that?