People around you have probably started saying move on, it has been months, he was not worth it. And you have probably started wondering what is wrong with you. Nothing is. Losing a person you were attached to sets off the same systems in the brain as physical pain and as withdrawal, which is exactly why it feels like both.
That also explains the part that embarrasses you most: wanting to contact someone who hurt you. That is not a character flaw, it is a craving, and cravings are handled with a plan rather than with shame.