Syncing FB

So I really screwed up and somehow deleted a ton of my contacts from my EVO 4G. When trying to add a few back from my call and text log, I noticed that they weren't showing up in my FB contacts - only about
50% of my contacts are showing. I went to sync accounts and only FB for HTC Sense is showing. Easy fix right? Just add sync account and add regular FB but it won't let me! FB shows up in my Add Sync account but nothing happens when I hit it. I turned my phone off and logged out of FB Sense but still nothing. HELP!!!