Can't you supposedly use a BB lockring on a suicide hub?

Look at your hub. If it's got a smaller-diameter section toward the outside, then just go buy a lockring and remember that the lockring bit is reverse threaded. If it's a continuous diameter, go invest in some red Loctite, make sure you're running a brake, and possibly a BB lockring (more info on the above from someone with experience would be helpful) and start saving for a new rear wheel. Otherwise, stop riding your bike right now.