Q.Why Is My Tomato Plant Wilting
I have a potted tomato plant approximately 3 feet tall. It looked very healthy when we brought it home from the nursery. It has been about 2 weeks and since placement on the porch, it has continuously wilted and is turning yellow. The soil is moist and have been supplementing with Miracle Gro. Fruit looks healthy.

Certified GKH Gardening Expert
Unfortunately, it may have a disease actually called wilt. This article has more information: https://www.gardeningknowhow.com/edible/vegetables/tomato/wilting-tomato-plants.htm