Help!!

Hi!! I've had this calathea since september and it was in great condition at first. I started seeing mold on the soil, and a bit on the stem, and also some stems were brown. When I saw it, I sprayed some antifungal and antibacterial organic product, but the mold didn't go away. I've recently put some cinnamon on the soil because I've read that it also has some antifungal properties, but it hasn't either worked (that's why the soil and stems looks orangish). I have my suspicions that it has root rot, but I'm not sure. What should I do or what do you see?? Thank you in advance!!