I have a sweet 100 plant and the leaves are turning yellow, then brown and dying. It started at the bottom but it seems to spreading up the plant.

The plant had been producing fruit for about 2 weeks but now some of the buds are dying as the leaves die.

I keep the soil moist and have fertilized with MG Tomato food once a week for about 4 weeks.

I have 2 other plants but they are doing fine so far.

What could be causing this ?

What should I do?

This is my first try at a garden and I dont want to lose my sweet 100s.