I'm in a very sad mood right now!!!

This topic is not intended for you to have pitty on me, nor it is intended to be critical of the poor judgments I made in the past. I had a full life, and I had my fun if I never be happy again! I am a man of age now (mid 60s) I started having sex with women when I was abuot 15 years old, I am an ex Marine of the US Armed Forces; so much for that, I will get down to my present life: 15 years ago, I married a 20 years old lady, to me, it was love at first sight! I'm nearly 51 years her senior. Things went well for the first two years or so. Then things began to go sour. She began to be unhappy because she says things like, my penis was not the size she wants, I don't have sex with her often enough, I'm not giving her oral right, and the list can go on and on. About two weeks ago, we came to a mutual agreement that we will live apart for a while to see if things will change with us, and she moved to Texas to be with her mother for a while. She called me last night and requested that she wants out of this marriage, and I honored her request! I'm sitting here right now, trying to put the pieces back together. My niece is living with me right now because her boyfriend and her has separated and she asked to move in with me til she can get on feet. I don't feel comfortable in the house with her because she walks around the house with little of nothing on, and it really does something to me. I came in from outside yesterday, and when I walked in the living room she was in there lying on the floor mastubating, and we both were shocked over the incident, I turned and went back out! Some mornings, she will come down stairs clad only in her panty and bra, and it appears that she does not shave down there because of the hairs that are outside of her panty!!!!