It is so hard to be in this situation, and get so much advice and not really know which piece of advice to use.
The BEST 180 is the one that is the opposite of his stereotype of you, not the opposite of you being nice or accommodating. If you want to draw a hard line, you need to be the most attractive option--the option that makes him happier.
He has a foot out the door, and that is looking the most attractive to him. Taking the hard line will probably give you the OPPOSITE of what you want it to do.
Assuming what you want is him back in, fully committed to your marriage, you will need to go about it differently. Find out what his complaints are (you seem to have done that) and do more of what works to make it workable for the both of you, and honestly, at this point right now, you would have to give more.
I feel this is probably not what you want to hear right now. But it will have a better chance at working.
