Try a larger pot and maybe a slightly less moist soil composition it almost looks like the plant is drowning at the stage it is in growth only other thing is molded roots. I hope not the latter. it can be saved if it is still alive and i believe many folks here can help you with different soil remedies. I don't see any diseases such as blights or or pests. so may just need to be fed some nutrients.

If your plant leaves curl downwards, then it is usually an indication of over-feeding. The feed youâÂÂre giving is too strong saturating outside the root membrane; so through reverse osmosis, water passes from plants across.