I've had terrible electro done on me on my first session too. I'll tell you what happened to me as I believe our damage might be similar. Ok good news: the colour will be back to normal in a few months. Bad news: the ''caved in'' part might not.
This is what I looked like a month after the treatment, still some redness: https://imgur.com/a/TrUDS
5 months in, the redness had faded away but the ''craters'' remained: https://imgur.com/a/5236g
I've had Dermapen treatments (micro-needling) after which worked a little bit, but I'm not quite convinced time itself wouldn't have done the same. The skin has amazing healing abilities! By ''worked'', I mean it seemed to have lessened them, but not completely remove them.
I could've had laser treatments too, but decided it wasn't worth it for me. I've talked to someone here whom had it done after several years past her electro damage and she says it has helped tremendously.
*Beware, ranty part*
Unpopular opinion but until someone proves me wrong (not based on hearsay), I'm convinced that laser, needling, chemical peels, dermabrasion and all those cosmetic repair procedures do the same thing, and you can easily replicate the effect at home without paying a hefty price. They either scrape (chemical peels, dermabrasion and to a certain extent laser) or pierce/remove (laser, needling) the skin. Only the degree of damage (because it damages the skin so it can heal itself back) varies between intensity and methods, but they all do the same thing!
I've conducted my own little personal research at home on this (still ongoing) so if anyone wants to come for me, you better have done yours too. I find the cosmetic dermatology field so vague that I can never find the truth anywhere, even the professionals/experts have different opinions...
*Ok, rant over lol*
I prefer my ''prepare for the worst'' approach so I'm not going to tell you that your damage isn't permanent, because chances are even if it isn't, you'll still see some imperfections.
Truth is, your brain will probably worry about this for a while (a year and a half for me), but after this, it too will ''heal'' and you won't have that nagging feeling of despair when looking at the damage, if you still see it.
Anyway, it's a bit difficult to judge based on your picture, try taking a few clearer ones with different angles near a window, if you don't mind.