Gosh and golly! How much soap did you add to how much water?
I know it is too late now, and not to make you feel bad, it is always best to wait until you've properly identified a pest before treating it and only then with the least aggressive treatment that is effective. You say you know you saw eggs, but of what? It might not have been a harmful critter while the treatment seems to have been...well, aggressive. But, I guess, on an optimistic note it does sound as if you did eliminate the potential pest problem on that plant.
Water under the bridge now.
The plant that has lost all its leaves is unlikely to recover; though if the roots are strong it could surprise you, plants do want to grow. Is it by any chance a pepper of the cultivar 'Lazarus'?
The plant(s) with scorch-like damage stand a better chance of growing through the damage. Unless you feel inclined to bathe it again - lather, rinse, repeat.
As a new gardener acquaint yourself with your county extension office or their website; every state has one and they provide good research and science based advice. Not only that, but it is generally specific to your part of the world.
Likewise, if you are researching online I think it is safest relying on information found on websites with the .edu domain name.
If you are new to this whole gardening thing then this may be the first plant you've 'killed'(?) In that spirit it is good to remember that if you aren't killing plants you aren't gardening. I stopped carving notches in my shovel handle for the plants I've killed decades ago.
Better luck with the next one!
Now step away from the dishwasher.
Don't know if this will work:
https://www.udel.edu/academics...