Attack of the tomato horn worm and other horrors

Over the last week or so, I've noticed that some of my pepper plants have lost all their leaves. A couple of the plants have peppers on them, but no leaves. It is very odd. Here's a photo of what they look like (ignore all the weeds that have sprung up around them!):
Today I was outside inspecting my garden, and I noticed what at first looked like a leaf on the pepper plant. Then I realized that it was moving. It was a caterpillar, and it's clear that he was the one eating up all the leaves. (You can see him here; he's the pale-green thing on the main stem of the plant):
He has also munched on the peppers on these plants, and there are big holes in them. YUCK!! I guess those are going out in the yard waste too.

Oddly, he hasn't attacked all of my pepper plants. It looks like he's only feasting on a particular variety of pepper - the California Wonder variety. My Cubanelle pepper has not been attacked so far.

I read on the Internet that this is a "tomato horn worm," which makes me worry about my tomatoes. Up until now, they've been totally fine. Apparently these caterpillars attack peppers, tomatoes and eggplant, which makes sense because I think they're all in the same family of plants. Later, they become moth-like creatures that lay more eggs.

In other news, I made pesto yesterday from the basil in my garden. As I was making it, I remembered that I grew garlic in my garden this year ... except that it's no longer anywhere to be seen in my garden. I really don't know what happened to it. Last week, I pulled out the lettuce that I had planted next to it, but I didn't pull out any garlic. It's just completely gone. I don't know if I just didn't notice when the stalks dried up, and it's still buried in my garden, or if the animals dug it up and had a garlic feast.

Really, it's been a crappy gardening year. Too much rain. Then my cucumbers and zucchinis didn't come up (which has never happened to me before). Then the stupid caterpillars ate my peppers, just when I was getting psyched that the pepper plants had lots of flowers. And then the case of the missing garlic. Really, if my tomatoes weren't doing well, I think I would just turn over the whole garden and plant buckwheat for the rest of the year. Better luck next year.