Hi, you sound like a very nice girl who does not deserve to be treated like that. He should be proud to be with you and put your feelings 1st.
I would suggest you sit down with him and express yourself to him in detail, and see what his reaction is. It sounds like he's failing to realise your presence anymore, and if he still wants to be with you, he ought to start caring and showing more affection towards you.
Hope that helps.