How To Handle Insecurity In Married Life?

Hi, I feel very sad and insecure whenever my husband go to a business trip. He is a very funny person in nature and flirting one as well. He doesn t call me as often as I would like and that keeps wondering who is he flirting and joking with over there. He gets very upset if I ask him any question. We do love each other very much and been married for 27 years.