Hello.
I understand that this is causing a certain stress for you. However, I want you to know that it is okay that you feel like this. Don't be hard on yourself for feeling like this. Since this is affecting your thoughts, it is important to talk about the same with your partner. Communication is the base of any relationship, it is this factor which makes or breaks a relationship.
Next Steps
Let your partner know how you are feeling. It is okay to express your thoughts. Look at how your partner respond to the same and can come to mutual decision. If you are having difficulty to communicate your feelings, write down what you would like to tell him first and work on the same so that it would be easier for you to speak to him.