Relax...you don't KNOW anything. Remember, no expectations. Even if that is what he says that does not mean you have no time left, many have reconciled even after D.
Look at the validation cheat sheet posted by Wonka. That will help. Also, look at some other threads, I know there are others who had the "talk" and did very well with the validating and still letting their S know it isn't what they wanted without begging, pleading etc.
Do something fun this weekend and take care of your self. As far as FB there is a way to block him from seeing your posts without unfriending him (my H did it to me).
Me-44 (45) H- 50 (51) M-'96
S-18(20)D-15(17)D-12(14)
BD Feb 2014 (he works overseas) home Oct(sep rooms) (EAs possible Pa's unconfirmed) insists wants D through July 2015 no more talk of D since