Help Black death eating my plant

Noticed it had a mite prob so it sprayed it with white oil that I got from the garden store. a few days later it had black dead spots on it? picked them off, now its back with a vengeance. Please tell me it not fatal

overall it looks healthy, maybe give it a rinse with a spray of clean water to remove whatever chemies is in that stuff you sprayed. Your plant should be fine.

Is it just me, or does the soil look really wet in the last two photos?

Looks like a deficiency to me
lol black death.