I screwed up trying to install a new temp gauge (replacing my useless prosport). The new sensors is 1/8 NPT which I though was the same as the prosport's but maybe not. I think while taking out the old sensor the threads got destoyed, I can't thread the new sensor in. I was going to plug the hole with the old sensor until I could figure out what to do but it only threads in half way and wiggles side to side a little while it's in (turned the car on and it's obviously leaking now).

How do I go about fixing this?