What to do with Droopy Cactus

I have a Cactus I have had for several years now, it is about 14" in length. I say in length as it is growing horizontally. Many years ago it just seemed it was going to die and started to droop. Then started to grow again but by now if was at floor level so started growing along the shelf.

I have no idea what its proper name is for the cactus, the body is round and the spikes are on raised little pimple like noddles. The spikes are like very fine needles. The spikes below the point where it started to droop have turned a dark colour like they are dead.

Any suggestion what I can do with it?

 

@Dorset-Tim, I'm not an expert on cactus at all but there are some on here who will be able to help. However, I think they will need a picture if possible please.

 

Most cacti fit that description so could you upload a photo please, also showing the part that droops. Many cacti also have a naturally pendulous habit so a photo is what we need.