The photo is too small to see details in the damage, but google four lined plant bug and compare to that.

Not a disease. Instead, environmental stress -- that's a lot of plant for that small container.

Its not environmental stress; like I said, all of my plants look that way, even the ones that have been transplanted. I haven't planted any more seedlings into the garden because I want to get rid of whatever fungus/ insect damage this is.

It does look a little like the four lined plant bug damage, but the spots are irregularly shaped. I got some all-purpose insecticide/ fungicide anyway.

The stress you are making your plants endure is likely making them susceptible to pathogens. Likely some sort of fungus, but the pic is too small to scrutinize to give any certainty.

Dan

When "all of my plants look that way" it's not a living agent such as an insect or disease. Instead, it's environmental stress.

Further, sometimes differences among problems on various plants are very subtle. So if we had more images -- larger one, too, please -- that might help us help you.

I agree with the others, but since you mention a lot of recent rain, my best GUESS is that it's a fungus.

seriously doubt that. Lots of rain often means environmental stress.

A larger image might help us know for certain.