I hate Facebook!! KIND OF LONG

My fiance and I have been together 3 1/2 years. About a month ago I told him his BIL tried hitting on me a couple of times and i hid it from them because I didn't want their kids to be without their dad but he kept trying and I got tired of it so I spoke up. My fiance thought I had cheated because his BIL made up crap about me but he's an a**hole so what is there to expect. Anyway after about two weeks after I told so he changed with me from one day to another, he went from being extremely mad at me to being EXTREMELY happy but now I feel like he's just with me to get me back. No I didn't do anything but he thinks I did. Or thought I'm not sure. Anyway I confronted him about how I felt he of course said no I would of left you blah blah blah but I still don't have a good feeling about this. Anyway he sent me the last text at around 9:40 PM, I replied at that time, he didn't reply anymore so I figured he was asleep, I woke up right now 2:16 AM, get on my fb and find out he was online about 2 hours ago. That means he had to be online around 11/12. Last night I woke up 4 something AM, he had last texted me at 11 Facebook said he was online '59 minutes ago' AT 4 IN THE MORNING. Clearly he's up to something, I arranged lunch with him tomorrow so I can confront him yet again! And hopefully this time he'll tell me the truth. Maybe I'm overreacting but if you're up at 4 or 6 AM send me at least a text and let me know you're up. If not to me that looks shady, or am I overreacting? Ugh! If I didn't have family living so far away I would completely delete my damn fb and talk to him so he could delete his as well! :(