I just did an emergency transplant. I changed the soil (with the previous soil, it was too sandy aka heavy), so I replaced the soil with mixture of 1 part peat and 2 parts perlite (for a more airy mixture).

On top of this, I replaced the plant with one of my healthier cuttings. When I uprooted the previous plant, it basically fell apart. I planted the remains in other pots in the hope that they may take root or something.

In the meantime, I'm focusing all my attention on this new cutting. It doesn't have much root system, but with a better soil (and not as wet as the other one), and more light, I hope to have some success in keeping this species in my collection.