Countershaft threads bad...

So today's episode of how I broke my bike... I've been doing a ton of maintenance this week including changing chain and sprockets. I went to put the new countershaft nut on and it looks like the threads are a little dinged up. The old nut can be screwed on about two revolutions but the new nut won't even start. What are my options here? Am I completely screwed or can I fix it with a die, if so does anyone know the size and pitch I'd need? I'm scared of screwing this up so bad that I have to have the shaft replaced , I really don't want to pay for that!

Try a thread file first to see if you can clean up the threads.

You will need a 27mm die, but don't know what the pitch is.

Forgot to respond to this, sorry for late reply. I decided to bite the bullet and take it to the shop. I was worried I would really screw things up and make a minor problem into a huge one. Cost me $78 for the guy to slightly bevel the shaft and fix threads. worth it for my peace of mind:)

Do you have any pictures of the now fixed threads? :)

I don't the shop installed the sprocket and nut so there is nothing to see