Maybe it would help to re-read some parts of DBing, especially about the point of going dark and the last resort.
DBing at bottom is about getting unenmeshed and becoming responsible for your own happiness while you give your P space to figure out what he wants.
It doesn't seem to me that you are in a place where you can be loving and supportive in a detached way. Rather, your motives seem to be still driven by fear and neediness. Let go. This doesn't mean shut the door, but let go and quit trying to control the outcome. Get OK with whatever outcome occurs, then maybe you'll really be able to share some kind of healthy R with SO.
This self-disrespecting, self-sacrifice doormat victim kick isn't good for anyone, trust me.
If he wants you as a GF, he can make plans ahead of time and call you and take you on a nice date that ends on the doorstep.
He doesn't need to wake you up in the middle of the night to have contact with you. What is that about? False reassurance for you that he isn't with OW to keep you on the line? A coping mechanism of his to keep him from calling a groupie and having indiscriminate sex instead of going home? A way to numb the pain of the life he has chosen? All these are his problems.
Above ALL, DBing is quitting your efforts at fixing another person's problems and controlling their happiness and general success in life. You aren't SO's parent and you aren't God. If you need someone to mentor and protect from themselves other than your own children, go to the Girls or Boys Club.
