Supposed to be working

So my husband works in the middle of the night. He used to tell me all about work, now he tells me nothing. I wake up in the middle of the night most nights because I have trouble sleeping without him. I just looked and he's on Facebook. I don't know what to think, he's a driver so how is he on Facebook in the middle of the night if he's supposed to be driving. And his phone will ring when he's on the way out the door sometimes and he won't answer. My ex- husband cheated on me for almost our entire marriage (11 years) I can't go through this again. He's been a jerk lately although we've had a very stressful month. Idk maybe I'm overreacting but I just see signs.