Beginner Gardening: I've killed them...., 1 by Kdmalkmus

Kdmalkmus wrote:
This is my first year gardening myself, though I always helped my parents growing up (apparently I wasn't paying attention). I started my early seedlings inside and I guess I went wrong somewhere. I have always had them under grow lights, but the tomatoes are a bit touchy--everyone else is happy! I noticed a week or so ago that they were starting to droop and now they are yellow and the leaves are falling off. Some leaves are curling upwards and some down. Some no longer have leaves. Some are brown on the ends and some have yellow patches. There is so much wrong that I don't even know where to start. I imagine it is probably too late to save them. I have started to harden them off in preparation for going outside in a week or so, but it doesn't look like they will make it that long. Can't tell if I've over or under watered. I've googled like crazy and it looks like both! What did I do wrong? They are so sad!

Usually I stick my finger in the soil and if it is just barely damp an inch in, I give them some water. Thought maybe that wasn't enough, so have been giving lots of water the past few days and that doesn't seem to have helped. I was probably overwatering to begin with and have now completely drowned them. HELP!