I'm so sorry this happened to you.
I think your fear is completely natural and even healthy at this point. Your husband cheated on you, twice, with your friends. This last time was recent, and with your best friend. You have a right to be fearful of him and other loved ones hurting you.
I'm assuming he was intoxicated this last time as well? If so, is he talking to his IC about why he abuses alcohol? Setting limits for himself? I was an alcohol abuser in the past, and it definitely contributed to poor choices for me. I think that is something that needs to be addressed. If your husband was drunk on NYE, then your emotional safety depends in part on your husband tackling his mis-use of alcohol.
Also, are you in IC? I hope so. This kind of trauma is devastating. Make sure you are taking care of yourself and your mental health. Do you have good coping mechanisms in place for when you are feeling especially down/stressed? The gym? Journaling? Walking the dog?
Your husband may truly be remorseful, and that can help, so, so much. Don't be afraid to ask him for any and everything you need to feel safe.
ETA: I understand not wanting to experience the hurt, but the only way through it is through it. I tend to try to rein my emotions in too, and my therapist always calls me out on it. Let yourself cry. Just know, as you do, that you WILL get through this. Journaling your pain is another great way to allow yourself to feel the sadness, and then heal.