My husband starves me of sex, what should i do

I am female, 36years old, and i have being married for 8 years. Lately, I have felt very ignored and restless in our relationship. I have spoken to my husband countless time but he has played deaf ears.

He buys me beautiful gifts and foots my bills, but that is where it ends. He has always been a very kind man, but he would rather watch TV and talk to his friends on phone  than talk with me.
Sex is just once or twice in two weeks.Recently a man has come into my life that rekindled feelings in me that have been dormant for a long time. I find myself thinking about him often and wish I could be with him. I feel so guilty and ashamed of these feelings, but nevertheless, they are there. I try not to think about him, but I do.I don’t know if he feels the same way about me, but sometimes he looks at me in a way that gives me a signal that he might. Nothing has been said or done between us. I don’t want to tell my husband about this because this man is my husband’s office colleague. Please help me out because am drowning in this marriage.