My husband is insecure.

We have been together for 5 years. We both have issues but we're perfect for each other and have worked through most of them but I can't get him to fully trust me. I have never cheated or anything and when we became official I cut all men out of my life, a bit extreme but I knew he was the one and my one friend was the one that my husband's ex girlfriend cheated on him with so I didn't want to make him feel insecure in any way. Anyways, we will argue because he will say things like "who are you getting dressed up for? Why are you doing your makeup/hair?" (I'm a SAHM so it doesn't happen often) We have security cameras, he uses my Facebook (only social media I have besides this) and has access to my phone, none of which bothers me. But today there was what seemed to be a spare car key on our porch (I have no idea how it got there and we're kind of in the boonies so it kind of freaked me out) and he just shut down. I knew exactly what he was thinking when he started acting weird. I told him to check the cameras to see if one of the delivery drivers sat it down maybe but he said he couldn't get it to load. I try so hard, I literally stay home all day so I don't know how I could meet someone new but he still has doubts. I've been cheated on before too so I get those thoughts but I never accuse him. How do we get past this or is it something that will always come up?