Did you make any other alterations at all? We are pretty nearby each other, I'd be happy to take a look at it for you and I'm free all weekend.
It kind of sounds like the mainspring may have popped off somehow, but you would be able to push it back forward manually if that were the case. The trigger wont come back all the way because whatever has your hammer hung up, has it in the position where they are impacting each other. DO NOT force it. That's a good way to invest in new parts.