Welcome to the wonderful world of growing tomatoes in containers. Here is what I've learned over the years. You water them too much, they wilt. Water too little, they wilt. Potting mix drains too quickly, they dry out too fast, they wilt. Potting mix retains too much water, their feet get soggy, they wilt. Fertilize too much, they wilt. Fertilize too little, they wilt. Give them a funny look, they wilt -- and then produce tomatoes with blossom end rot.

I know this is a little late, but I have had the same problem with my peppers this year and I thought initially that it was P or Cu deficiency but later decided (with the help of Dr. Riechers at the University of Illinois) that it was most likely 2,4-D or dicamba damage. The key to identifying is epinasty (the leaves veins should not run more or less parallel such as in the case of grasses and should be perpendicular to the main vein). I too did not use either of these herbicides but I live near a corn field that had been sprayed by an airplane. I did not know what the plane was spraying but this is the most likely cause. Here is a link that might be useful: The Medicinal Pepper

I have the same issue going on with my Mortgage Lifters...did anyone provide any insight about what is causing this for you? Did the problem get resolved? Thanks!

If I understand you correctly then yes, WAY too much fertilizer. And that explains the aphids - they love all that excess N. 1-2 staged doses of very dilute 1/4 strength of normal is more than enough for most seedlings. And, if you used MG Gardening Soil rather than their potting mix then that too could be part of the problem as it is not made for containers (it's on the bag) and there have been several reports of problems with it in the past here when it is used in containers. The Neem also needs to be used at a diluted strength on seedlings as does anything you use on them. They simply cannot tolerate the normal doesage mixes recommended for established plants. If it were me I would hose off the seedlings well with the sink sprayer to remove the aphids, flush out the root balls to get rid of all the extra fertilizer, and repot them in a fresh, neutral potting mix. They may very well recover. Meanwhile, start some new plants if you have time. Good luck. Dave