There are a lot of possible sources of the feelings of guilt. You could have a sense that you are not fully hearing out and considering the needs of your spouse and son. It could be that your choice to leave would be contrary to what you were taught in childhood. Perhaps you feel in your heart of hearts that you should give the commitment itself more of a chance. Maybe the guilt is none of these things, but something else altogether.

Perhaps individual and/or couples therapy can help you understand the guilt better and come to terms with it, and thereby help you to find peace in whatever decision you make.