What if you are afraid because you do see signs of what you think is a cheating partner?

My details are, my friend/lover/signif partner-whatever you want to call him, has always ben known to his family and friends as a player/womanizer. He claims to this day hes never been with anyone else, but his secretiveness makes me leary. He has a phone he claims is a work phone, he is always gone to play cards w/the fellas. He wont be seen with me in public, but we do live together. I tries really hard at times to let me know where he is and what he is doing, but because of my past with my X cheating on me, and then his past as well, i have a hard time accepting that he is being faithful. How can you just let your guard down and relax? This is probably the worse thing going on in my life, it makes me mad, scared, leary, paranoid. And to top it off, I may be running him away, because I am constatntly checking up on him and trying to verify his story, only to call him a liar in the end. HELP!!!

Update: November 18, 2009.
Lmark, that was really cute and funny; thanks. However, we have only been on one or two dates, in the almost year we have been together. And that was at the beginning of our dating. I have met his friends, but they dont go on dates with us, they came to my house for a cook out, or I have met them when they come to our current house. I have also met almost all of his family, so I dont think its the psycho thing....any more clever responses?

Update: November 18, 2009.
Thank you all so much for your words of wisdom. Although one or two a little harsh, I appreciate your honesty. To answer some questions, Im not sure 'he wont be seen with me in public', I feel more like thats how I feel because we never go anywhere together. Im not only with him because of my love for him, but his daughters as well. They are in need of direction from a woman, and they have made me realize how much i miss motherhood. As far as the phone goes, I have gone thru it and it is a work phone, I have also gone thru the phone we share on a plan and never run across anything that I shouldnt have; except porn, and I dont have a problem with that. Like my kids and best friend say, Im looking for something that doesnt seem to be there. Although he plays cards a lot, he is also home by 9pm, and is home by 6pm almost every day; and hasnt slept away from home. Nonetheless, he has been a womanizer up to the (so he says) point we met, but he also says Im the only woman he wants, because I am the full pkg. I hope I addressed everything everyone said. Thanks again, look forward to reading your responses, if you so choose to rerespond.