I think your boyfriend must love you a lot to stand by you when you are being so difficult. Please listen to him. What you are describing is consistent with a diagnosis of depression but only a mental health counselor who actually talks to you can confirm that. Even if you are not “clinically” depressed, you are certainly having a tough time. A counselor may be able to give you the support you need to take a closer look at why you are so irritable and why you are gradually reducing your world to your own four walls.
If you are too anxious to go to a first session with a counselor by yourself, ask your boyfriend to go with you. He can help you describe what you have been like and how it’s different from when you were more able to be your best self. By taking yourself seriously enough to get help, you will be letting him know that your relationship is as important to you as it is to him. Just as important, you will be breaking free of the cycle that is isolating you more and more.
I wish you well.