How can I make it right?

Me and my boyfriend have been together for about 6 months now, not long, but long enough. I let him into mine and my daughters life, he became my best friend and the father to my 5 month old daughter. We have been having problems, we both have faults but it feels like things are just going down hill. He became a cop and ever since then I have been spiraling down into a depression, he has lot's of girl friends and guy friends, but I know for a fact that he would never cheat. But yet I accuse him of hiding things from me and I go through his phone after he asks me not to...only to find nothing. I get mad over the littlest things, he hasn't had any drive since he started working as a police officer, and I know the stress of the job and on top of that working 2 other jobs as a security guard and fireman can only add to that stress, But I feel as if I'm not good enough, or pretty enough, or something is wrong with me. I ask him every day if something is wrong and it is starting to get to him, and I can understand, it would get to me too...but how do I make things better? I have lost his trust and respect and I want it back! I just don't know where to begin, and I don't know if it's too late?!?! How can I get over these insecurities within myself???