Tomato Wilt maybe

[Di Taylor]

I have a big problem with my tomatoes, I am losing plants and I think from the description in my pests and diseases book it's a wilt of some sort. My dilemna is working out how its all gone so wrong, I'm sure it wasnt anything in the soil as the garden my toms are in this year was lawn last year, I covered it with newspaper then layers my own semi-rotted compost, lime, peastraw pellets, dynamic lifter (a commercially prepared organic blend of blood and bone, sheep pellets, mushroom compost, seaweed etc) and lots of commercially prepared compost, i let all that settle for a month or so before planting into it. The seeds were purchased online from a private seller, not commercial seed and I understand these diseases can be passed on through seed. I can see how as my fruit on the toms is lovely but I dare not keep the seed if thats the case. Attached are some photos of my sad dying plants. Can I have help confirming ID of disease and suggestions for prevention.