I need advice

So a friend and I(who I met through work) ended up sleeping together one night. We kept hanging out and it kept happening. We were messaging on a regular basis and I miss you'd and such were said. I'm currently going through a divorce also forgot to mention that. Any way. A few days ago we were supposed to hang out and he texted me several hours before saying he had bad news and couldn't hang out. I asked if something was wrong and said ok and he hasn't replied since. He's reading my messages and ignoring them. I asked if he was mad at me the other day and he still hasn't replied. I looked on his Facebook to see if anything was wrong and that's why he didn't answer and all I can see is his name and picture and nothing else. I can still send him messages there and everything I just can't see his posts. I don't know what I did wrong or if he's mad at me. I'm so confused about what to do. I have to see him Monday at work and I don't want it to be wierd. Any advice?