I recommend reading To those I love who still eat animals. It really showcases how you can maintain relationships with your friends and family while maintaining an antispeciesist stance. I think the pledge can be conveyed in a loving way, without being exclusionary or having to cut off your friends. You may be surprised at how people take your feelings seriously.
There are also a load of success stories on this site you should check out. The pledge works. All these people have kept their family and friends.
The reality is, if you’re antispeciesist, you’re going to struggle with family and friends anyway. You may as well take a stance on it.