Throttle lever not springing back

My bike is a typh125 2T. so I needed to adjust the pitch off my front brake lever on the handlebars to bring them pointing slightly lower. In the progress I clearly tampered with something by mistake and now my throttle lever is not springing back.
There is a very short threaded flat headed screw directly underneath which I tampered with. The spring wrapping around the lever is out of place. I've tried popping that tang back in but it still doesn't spring back. How do I get the throttle handle to spring back?

 

Upon troubleshooting I've found that the cable that slots into hole on the twist grip has snapped. I've cut back the bad strands as little as I could but it doesn't seem like it's going to give me enough cable to clamp on to. I'm thinking a new throttle cable if anyone says otherwise?

 

Fit a new cable and lube the throttle tube.