tomatoes wilting on vine-help!

can someone help me?
I'm a NEW gardener, tried this year to do tomatoes in pots on my deck as it was more convenient. started late as usual
have tons of tomatoes, large, different sizes really, but they have been green forever and not progressing.
finally today I noticed 3 are wilting, or puckering. it is BRIGHT on my deck some of the leaves are a little yellow/brown but I think it's sun--I dont see any obvoius fungus or insects.
I still have many good tomatoes that I hope will ripen before it's cold.
we didnt have that much HOT weather this year but tons of sun.
is this from watering too much? because the pots (they are huge) seemed to dry out I was watering every day. if I stop the plants wilt and dont look healthy. i was afraid they were dying from lack of water. also I went away some and had the cat sitter water them. maybe from UNDEr watering?
advice to save what's left of the tomato garden I've worked on all summer? thanks! theresa