plz don't tell me i have to start from square 1 i have nothing other than the game post-export
It is impossible to recover the source from exported projects, for quite obvious (anti-piracy) reasons.
You should always make use of the auto backup and auto save functionality within C2. This will not only save a local series of backups, but also create a backup off-site (Dropbox for instance) for just such a bad experience as this.
Unfortunately this is a very difficult lesson to learn - one we have all experienced at some time.