BTM. As horrible as this might sound to you right now, congratulations on making this choice.
My sister has been living in a loveless M for at least ten years now, maybe more. The result of an A BIL had those many years ago. I'm sure W has not forgiven him completely, but stuck with it for the kids and so that she could at least say she tried.
As many mention around here, we all have our breaking point. I hate to think I'm "weak" and don't have the perseverance to keep going, longer. But when "the writing is on the wall", I accept that moving on is the only option. In my sitch, I will not hinder the progress, although I will neither accelerate it. I would do what I need to in order to repair the M, but I will not pursue that with a person who is (has become) someone I do not wish to be with. A person who continues to move away, rather than move towards.
Dating does not have to be "intimate", even thought that would be a natural progression to moving on with someone else. It is simply a step towards getting your emotional needs met and learning to give to someone else now. As it starts with establishing new or progressing existing friendships.
This board and I'm sure many of your family and friends will support you in this new life you move towards. It might be time for you to consider filing. I'm sure you did not want to be the one to do it, but for me personally, getting D is a necessary finish to be fully able to move on.