You’re correct. You are being overly possessive — and you are putting your wife in an awkward position. Of course she isn’t as intimate with you, when the two of you are with her parents. That kind of intimacy is a special bond that belongs with the couple. When she is with her parents, she needs to give them her time and attention as well. She loves you. She loves her parents. Because you won’t join in with the family, she feels she has to divide her time between you. I imagine this is more stressful for her than you realize.
You are hardly left alone. You have a home and a little girl. You also have the supportive extended family most people would wish for. This is not your wife’s or your in-laws’ problem. It is yours. Work on being grateful that you have a wonderful family and a wife who maintains the connections among all its members. Focus on getting to know your in-laws as people instead of seeing them as a threat. (They’re not.) And don’t think about moving further away. My guess is that will make things much worse for your wife and consequently for you as well. If you can’t get over the idea that you are competing for your wife’s attention, please consider seeing a therapist.
I wish you well.