IMO, it is far better to set goals for yourself and where you want to be on this journey. Giving yourself a "give up" or "move on" date is like secondary control.
Give up on waiting for him. Move on with improving yourself.
This does not mean stop standing for your marriage, it means giving up any semblence of control over the situation.
When I was where you are on my journey, I felt exactly the same way. Last October is when I finally dropped the rope, realized that I didn't have to hate him to let him go and filed for D. I didn't want to go another year, another holiday season or another anniversary in limbo. It was MY end of the line.
In November, H started coming out of the tunnel, spent Thanksgiving with us out of town for 5 days.
In December, H spent the holidays with us and when I found out afer Christmas he was still seeing OW, I told him no more.
In January, 6 days before the D was going to be final, H asked to delay the D.
In February, spent V-day together and had several really good R talks. He asked me to be patient while he learned to be a better man to me and to himself.
In March, spending most weekends here and we are seeing each other almost every day. More good R talks and H telling me how sorry he is about everything he put us through.
The key FOR ME was to completely let him go. Not just to say it but to do it and mean it. When you get to the point that you know you will be fine and your life will go on and be great because of what you choose to do with it, that is the time to move on.
Just don't shut the door completely.
"No one can make you feel inferior without your consent." -Eleanor Roosevelt. M-42, H-42. M-22yrs, together 27yrs, Sep 5yrs. D-22, S-18 I'm a survivor