Hello Paradajky,
I've just arrived from the "wilderness", i.e. our cottage. No computer, no TV, no smart phones.
I am really sorry to see the plants in such a state. I've done some research for the causes. I don't know if that can help, but the results are interesting. SSM is resistant to Fusarium wilt but only race 1 and definitely not to Septoria. The significance of FW races is that Cal usually gets hit by race 2 and 3. Here's the link but I am almost sure you've seen it.
https://vric.ucdavis.edu/ucd-access/...Dec%202014.pdf
To me it looks like you've been very unlucky: 2 really bad pathogens in one garden (I still believe it's sls in your SSM). And what's even worse: they both love hot weather. Better luck next time.
Milan HP