(((Avalon))) Please reach out for help. There are people who can help you with the grief and the flood of emotions you feel. I know you won't believe it, but your feelings will not kill you. A counselor can help you find your joy again! You do deserve joy. You do deserve a peaceful and drug-free life and partner.
I broke up once with someone who I thought was the 'love of my life'. I said the same things you are saying now. "I have never felt this way about anyone"; and "I can't begin to imagine loving anyone else".
Well, I have been married now for 3.5 years to a wonderful man, and we have a beautiful, healthy relationship.
In time, with each passing day, your pain will lessen, your sleep will improve, your appetite will improve, your laughter will return. I promise because I am speaking to you from the other side of this ocean of grief!