Welcome, Laurene, sorry for the pain you are going through. Glad you found us.
You say you don't know what to do so I encourage you to focus on healing and recovering from the relationship. I know you can't see this now but he has done you a favour. This is not a person who can emotionally give you a good and happy relationship. He just doesn't have it in him.
Addicts will often try and keep their former partner on the back burner just in case the new one doesn't work out which seems to be what he is doing by telling you he still loves you but wants to date the new one. If you stay hooked into this, it will lead to more heartache and pain. For your recovery you need to go No Contact with him so you can heal and the Trauma Bond you are in with him can heal.