Go with my Gut?!?!

Ok so here's the deal.... I'm 3 months post partum and a fucking wreck honestly I'm pretty sure I have ppd but that's a whole other post! Anyway me and my husband have been together 10yrs and we have never fought like we do now and before you say anything about the baby it's not him our 18yr old son (my step son) moved in with us 2 weeks after I gave birth and let's just say it's been a complete nightmare. I'm freaking nervous as hell that my husband has or is messed around on me, I can't put my finger on it but stuff just doesn't add up... I found a friend request on his facebook that he sent to a girl who he cheated on his ex wife with when I confronted him he said someone hacked his account I looked at his logins and there were some that weren't our devices but still who from 15 yrs ago knew about that skank and hacked his facebook and knew that would cause a lot of drama?! I just feel like I want to explode and cry and just blah all at the same time! I'm self conscious right now I've lost all my weight except 10lbs but I still don't feel like myself... We have had the most amazing sex since I've had our son and he compliments me on my body but he's not the same either... I've caught him in lies but then he makes it out like I'm the crazy one.. See what I mean it's just F&@?!$&&!??.... Sorry for the stupid rant I can't sleep and just need some advice help please!!!!