I am a BS, but both my spouse and I were both wildly insecure for quite some time. He was afraid he would come home and I would be gone, any day, any moment. I felt like someone had removed my skin with a cheese grater and left a bloody footprint with every step I took. I felt like people could SEE inside me for a really long time.
You know what? Embrace it. It is scary but you will grow through this experience.
For my part, I promised that I would never disappear on him - unless I caught him cheating again. Barring that, if I decided I had to end things between us, it would be a conversation face to face. It gave him a bit of comfort in order to keep fighting the good fight.
Hang in there and make good choices!