How can i fake emotions ?

Before I start I don't want any bullshit about being a serial killer or sociopath cuz I've heard them all....I was generally a happy person full of life until about 4 Years ago l..my recent ex girlfriend rocked up at a party I was at drugged up to the eyeballs weilding a gun. Naturally we all dove for cover she went on about how much she loved me and how I hurt her. Before turning the gun on herself she pointed it at me and said this is all your fault. She then turned it on herself. Ever since that day I have been blank trying to train myself to feel again...I now have a wife and a daughter and my wife is starting to see through my fake emotions to the point that she has considered leaving me. So my question is how can I fake all these emotions when she can see the blankness in my eyes