Josy, I cant imagine how you are feeling right now and I am so sorry! Hopefully, you can explain some of the other ways you can be together and he can get his head around them so he feels more comfortable. My guess is that he's scared and does the "cut and run" move as I often do. (and I will admit, I have thought of doing it a few times even in this relationship). He could be thinking that the pain of being seperated isnt worth it if there is no reward at the end for either of you. Fear makes people do irrational things. When people have well developed defense mechanisms, they usually end up causing more harm than expected.
I made me tear up to read when you said that hes broken many promises to you. Its the worst thing to trust someone enough to believe what they promise and then be let down... (sidebar: which is why I am not at all encouraged by what David said on Friday night, Jamie. People can say anything they want, but its the actions that count, and I feel that familiar empty pain in my chest when I think of how many times words have been only words).
I forget Josy, how long have you and Jason been together?