Do you often find yourself canceling plans you make with your friends or family? You can’t have turned socially distant all of a sudden. Either you are too burdened at work or drained handling this relationship.
If the former isn’t the case, then certainly it’s your partner. If they decide to take you out on the same day or plead you to keep them company, you should know that all they want is to distance you from all others who are special to you.