Need to say this: Please replace hell in the title with "spoiler" or something like that. Don't want to ruin the surprises for new players. I'll read the post after this, but the title definitely needs to be changed. Modify the first post to change the title.
Looks like a pretty Fun fortress death. Since you knew about adamantine, did you know about the demon hoard that was going to spew out once you mined to the end? That's generally a fortress breaker.
No way you're going to survive this. I recommend not even trying to reclaim. Your parties will just get slaughtered and/or arrive at a completely empty fortress. Just make a new fortress - they all have to lose at some point!
As for posting the save file: The saves are found in the DF folder, under data/save. Each region is one save file. If you want to host it somewhere, you'll probably have to compress it into one file, through a program. There's something called the Dwarf Fortress File Depot - it's made specifically to hold DF game saves, mods, and the like. That's where you'll probably want to upload the save to, but other sites work just as well. After that, just post a link if you want others to download it.
And to elaborate on the spoilers: These forums generally follow the wiki's policies on spoilers. If it relates to a page that has a spoiler warning, put a spoiler notice in the topic, and/or put spoiler tags around the specific subject material. Example unusable words are hell and demon. These can be replaced, respectively, by circus and clown, if you wish. Most minor spoiler wiki pages are discussed openly - stuff like Forgotten Beasts. Adamantine can be open, spoiler'd, or switched to candy or cotton candy, at your discretion. It appears on many in-game screens, and most people know about it, so it can be OK.
Not adhering to this won't get you banned or anything, it's just common courtesy.
Also, welcome to the forum! May you have fun losing in company!
EDIT: That works well.
Also, your first picture isn't working for me.