SOS!!!

So I have this majestic palm??? I think? I’ve been growing for like 9months, and it’s been doing amazing! Started with one leaf and I’m at 3 now and have been proud!!! Well recently I noticed browning on the tips, and then I investigated further to see black spots on the stems of each leaf….. I panicked and uprooted it, and gave it a good shower, but idk what the cause of this is from. Other than Indiana weather???? But it’s not near a door…. So idk….There were/are no pests and it’s been happy from the get go. It stays inside and about 5 ft away from a barina 10” grow light beside the rest of my plants with a humidifier directly beside it… can anyone help me with this before I lose my mind and chop it all off, please? Even the new leaf coming in the center is browning!!? It’s my O.G. First self bought plant and I don’t want it to die!!! 🙁