Missing in Action

My husband has taken action in an attempt to negate our problematic past. As I said he has done so before but never so earnestly. He is loving in spite of my continued distance. He frequently tells me he loves me so much and though I say it back I can't feel the conviction of it but I am willing to try so Ive given him my trust, my body and my support again.  He is affectionate without demanding reciprocation. He has not been porn shopping or ogling women. Hes been pleasant and apologized immediately the one time he slipped a little rudeness. I find it suspicious...the learned response I have but hope always wins. This is the honeymoon phase of living with a narcissist. So now that I "seem" to be getting what I asked for I am not satisfied by it. I've not put deep thought into it but it niggles...has he found someone hes talking to? Hooked up with? For surely its been my understanding that I could not possibly be the one to motivate him into love and happiness. So whether he is sincere or not I find myself on the emotional roller coaster of hope and no hope. It is a strange state of stasis. So regardless of his actions something is still....missing.