Planted my cherry tomato plant in a pot with vegetable potting mix about 5-6 weeks ago, grew really well and fast, used organic vegetable fertilizer and/or fish emulsion weekly.

Then started getting yellow leaves that would turn black/brown on edges, about 7-10 days ago. Seemed to affect more and more of the plant too. Local garden center said probably over watering, watered 1/day, sometimes 2x, recently as we have had hot day time weather >90F. Said its probably a fungus, so sprayed with organic fungicide and some leaves went brown - removed all of those.

Flowers and fruit still seem to be coming along tho.

Any ideas/suggestions would be appreciated!