"my special open face grilled cheese and tomato sandwich"
Now THAT sounds delish! I vote for that!
As for your plant, I've had tomatoes in a row, same varieties, that do what yours is doing and never figured out why some of them did that. Maybe that particular seed didn't carry a strong growth gene or something or maybe it got wind-whipped at some point, disturbing roots, etc. The garden sure is full of interesting episodes, eh?
Regarding tomatillos, yes, most varieties require a second plant but I've heard of folks declaring their one plant produced fruit. I've grown them, from grocery store fruit by the way, but always had more than one. I know they love heat and tend to produce later in the summer than tomatoes so maybe you'll still get some. Don't give up. Or if you want to play around pick a flower and rub some pollen on another flower, preferably early in they day and see if that encourages pollination.
Shoe (who just picked umpteen pounds of purple hull beans and needs to go shell them, with my latest Netflix of The Waltons entertaining me or course!) :>)