I know how you feel Michonne. I don't know how long ago your Dday was, but I kicked my WH out the night I found out. He was out of the house for 6 weeks. I think having him out of the house was the best way for me to realize how much I loved him, missed him, needed him and wanted him in my life.
I too have a long history with him. I missed having him in my life every day and his absence was difficult. I ultimately decided to allow him to come back and work on R. We have a whole life we've built together, 3 children, a home, and 28 years of memories. I decided to take this long difficult road for myself and my family. I really don't know what would be more difficult, divorcing and having to start a new life and watch him start a new life too and always denying my feelings for my true love. Or the staying together and working through all the pain that infidelity brings, always feeling an ache in my heart when I look at him and thing of him with another woman.
There is no easy choice.
This is our reality.
Look deep within your heart and decide whether you can live without him. I decided that it was worth the risk to try and save the M. I'm deeply in love with him and I cannot deny that. Its a battle between your brain and your heart. DAILY!!Having a completely remorseful H is just about the only thing that makes this difficult situation a little bit easier. If he is willing to put YOU first and focus on YOUR healing (and of course work on himself in the process)it makes your decision a little easier.
I also haven't told my immediate familY. I knew that if I told them, it would only be if I decided to D. I didn't want them to know in case I decided to R. The last thing you need when your facing the emotions of infidelity is a family member giving you their two cents on how you should leave him. When you just need to focus on what works best for YOU.
Hang in there :)