First attempt at mechanics, went pretty badly...

Sorry, I don't agree with your comments about Cycle Surgery. It all sounded fine for months and then you choose to neglect it further.

Well yes, I just called them cunts for using the excuse that I was too heavy for it. I doubt I have the power of Chris Hoy, it seems to work fine for him. If they had done it properly in first place, or had been willing to replace dodgy parts, it wouldn't have ever been an issue. They only told me the thread was fine, but didn't want to show me.

But yes, as soon I as I chose to ignore it, it was my fault, I'm not disputing that.

If you overtighten a lockring on threads you've already trashed then obviously it's going to fail. Replace it and learn how to take care of your fixed drivechain so you don't do this again.

That's the plan ;)

A Shimano chainwhip and lockring tool is a must have in my opinion.

Which is what I bought