Beginner Gardening: My Marble Queen is slowly dying, 1 by eargadin

eargadin wrote:
Please help! I have attached a picture. My plant keeps turning black at the steam. Not the steam the leaf is attached to, but the steam that connects to the roots. My plant used to be big and bushy and beautiful and now something changed. I haven't changed anything. I have tried cutting it back and I took it out and looked at its root but nothing looks unusual, unless I'm not looking at the right thing. Thank you for any advise anyone has!

Bethy