I do know how you feel, but in my case there were no arguments, we went from planning him moving to Spain to him ending things in the space of 10 days.
There's no answers tho, I feel that maybe when their heads are back in the place they were in when things were good, they may realise they miss you. Whether they appreciate the hurt they caused in the meantime is another matter. From the outside it seems like a very selfish illness but that is the defence mode of the depressed. They need all their energy for their day to day life and just can't cope with what they perceive to be the demands of a partner, even tho all the partner wants to do is support them.
I'm debating Whether to message a friend of his, just to ask If he is ok and If the friend knows what his plans are .... it won't go down well if his friend tells him I have contacted him but I don't know what else to do. I hoped he might remember his promise to be here for my birthday, but that was made when things were good, then I hoped he'd be here to see his grandchildren for Easter, but still nothing. If he is here I'd have no way of knowing. When is the time to give up, I don't know.
I hope you can find some peace in your head. I know how difficult it is. I have run myself into the ground this weekend (I have M.E. albeit very mildly now) running around trying not to think about him. It hasn't worked,must just made me feel worse.
Keep strong x