Lost and Confused

Hello. I am new to this site. I am 37 years old, married, and a business woman. But the sad thing is that I have no biological roots. I don't know anyone who is biologically related to me. I love my adopted family but for some reason I feel so disconnected with them. They haven't done anything wrong. I am an international adoption. I was adopted when I was seven but I look so different - different race, personality than my adopted family. But I just can't seem to connect with anyone even with my husband's family. His kids are not my kids- his family is not my family. I don't know what to think or do. I feel like I get so lost in trying to connect with people. Other times I feel like I simply don't belong anywhere. As I get older, I find myself distancing myself from everyone. At times I get so depressed that I have no close connections that I simply don't want to exist anymore. Any suggestion?