What should I DO about this!!!???!!!?

Okay this past week my boyfriend has been stressed cause I am stressed and feels sad because I'm being mean to him. Well, he told me he needed his time to think. We haven't talked that much because I've been letting him think and just giving him his time. Well, I went to a friends house to get my mind off of it because he was at a family picnic anyways. Me and him have been together 3 years now. But anyways, I asked him to please text me before he went to bed, he said yes I promise. And we left. Well it came to 11:30pm and I was like why isnt he texting me?... Well I texted him and no answer.. I called no answer.. So I called his house, his mom answers and she wouldnt tell me where he was.. She said he went out with friends.. I know he was drinking last night cause that is all his friends do.. But, previous to this.. I got on facebook and he had a pic of him and a girl on there I think it was his moms employee because it looks just like her but I'm hurting so bad. We are supposed to hang out today and I'm so nervous we're not.. What should I do? What do you think will happen?? This has happened before but usually he tells me where he is.. He eventually turned off his phone.. I know when he is stressed he drinks... So, I dont know what to do I need help!!! i'm freaking out.. His phone is still off!