camellia sinensis fungus/dieback? Help!
I'm new to growing camellia sinensis. I bough a baby plant a few months ago and decided to container plant it because its too cold where I live to leave it outside all winter. For the summer I let it stay outside, but then the green leaves started getting spots on them. In fall it bloomed, and had plenty of flowers on it.
Then the spots spread to all the leaves and I researched as much as I could on diseases, and decided it had a fungus that it caught from the outside environment. So I sprayed it, changed the top layer of soil, and brought it inside (its too cold for it outside now). It gets sunlight, but is in a cooler room of the house (like 65 ^F in there).
I noticed some of the shoots have dark stems, but I don't know if it is infected, dieing back, or what is happening. What can I do to protect it? What can I do to help it and get rid of the disease, or help boost its immune system? Is there a specific type of fungicide I should use?
Please, any help I would greatly appreciate it. I love my plant and I don't want it to die :( Thank you!