first off, I do not have your cactus and I am just guessing using the forum listed below. It is not the most complete site but it is a start. I do not know if your plant has been grown in good light so maybe what I am looking at is etiolated. Echinopsis camarguensis? Cliestocactus hildegardiae, Cleistocactus seplium,.. The corryocactus family might have one that matches. Echinopsis litoralis.

Cactus ID by habit site

So.. a little over a month later, i've watered once, it gets approx 6 hours of bright but not direct sunlight and now its all sad and floppy looking.. whats going on?! There are heaps of pups showing up though so thats good I guess?

I'm thinking about repotting into a better container but not sure if its a wise idea at the moment..

That pot doesn't seem to have a drainage hole does it? Which ever cactus it is (sorry, don't know), that's likely to be an issue.

Agree with Imonstella, it looks like a case of 'wet feet'.

If it was erect before and now flops like that, I would check the roots for water damage. What is it potted in (soil?). I would check for any yellowing and also check the stem by gently squeezing - it should not be soft & squishy, these are signs of possible rot (not easy to check cacti stems :)

I don't know this plant - just comparing before and after photos - there are some cacti that sprawl like that.

Personally, I like to see plants potted higher in the pot - filling it with more mix (not planting plant deeper!). And I would also move it into more sunlight (gradually).

Rina

Try Aporocactus flagelliformis. It's supposed to grow like that.

Yup Mentha it is a Flagelliformis, otherwise known as rat tail cactus! I was worried for awhile until I found out its supposed to be a droopy cactus hehe.

Imonstella, it does have a single drainage hole in the bottom, its an old record melted and shaped into a pot so has the record sized centre hole.