He didn’t realise me waiting like this was hurting me so much. He told me this morning again that they are merely co-habiting and I have to trust him. He has sworn he is moving out again imminently and if had known that me waiting for him would risk losing us he wouldn’t have asked me to wait so long. We will see.
Yep. What you'll see is that he'll come up with some more excuses for not leaving.
Do you really REALLY think he didn't know that waiting for a real relationship for FIVE YEARS wasn't hurting you?
Why do you 'have to' trust him? What foundation for trust is there in the relationship when he has been telling you one thing and doing another for FIVE YEARS?
The way things are now suits him just fine. You can know this because they haven't changed for FIVE YEARS. Anyone can change their circumstances in a five-year time frame if they really want to.
The only thing that will make a bit of difference and show you where his true priorities lie is for you to create some genuine consequences for him. You have to tell him, "Okay, well, I can't do this any more. I believe that you're leaving imminently, but until then, I need some space. I'll welcome you back with open arms when you leave." And then leave. Because when you tell him "I can't do this any more" and then go on doing it anyway, you're telling him that that your words are empty. You'll keep on accepting whatever crumbs of love he is prepared to offer, for as long as he's prepared to offer them. I expect you're afraid to draw a line in the sand because you know perfectly well that when push comes to shove, he's going to stay right where he is.
No wonder this has gone on for five years. You're probably so numbed out emotionally by this awful situation that the drama of an affair is the only thing that makes you feel alive.