Feeling Unsatisfied - Open Relationship

M30 Found true love at the age 18, got married at 25. Explored open relationship at the age of 22. My wife had great physical experiences between 22 to 27. I have barely had one or two encounters. We are emotionally connected with each other. We are at that point where we want to have a kid. But I am have this extreme feeling of unsatisfaction as I have not had many physical encounters neither with my wife nor with others. My wife isn’t that excited in having sex with me. When she was physically active we would make out once in 3 months. She would have similar frequency with others. But now she is not interested in physical encounters with anyone. Even with me the frequency has reduced to twice a year. We want to have a baby soon as she has crossed 30. But I feel that I have a lot of pent up feelings of romance that I want want to experience before having a kid with my wife. I have the permission from my wife to experience that with anyone but I am just not able to. Since two years I have been going to clubs every weekend but I just can’t approach any girl. I have this fear of rejection and I expect the girls to approach me which has happened just twice but things worked out only once. So off late, I have given up hopes of experiencing romance. Any suggestions?