I do feel for you.
I understand all your frustration and anger, and hurt, which jickey for position in your mind.
Grief - and that is what this is - is a process that has to be ensured, there are no short cuts.
Some days you will feel OK, happy even, other days you will be desparate and distraught.
Know that these swings will even out as time passes, and you will get past this horrible feeling of anger and abandonment.
Try to make yourself not look at your ex's Facebook, it's only hurting you - hard to resist I know, but that pain is just not needed right now.
Come back if you need to talk again.
A x