I worry when I hear the "I need space" line. You and I are veterans of these things. 99.999% of the time when a spouse says "I need space" when suggesting separating what it really means is:
"There is an OM/OW and I want to pursue something with them. I'd like you to hang around as my fallback plan in case that doesn't work out."
I wish that's not what it mean but it almost always does. I feel you on the detaching. It can be tough. I couldn't do it and then one day it just happened and I was detached. That has been a challenge for us during our reconciliation and reconnection. My W is fully attached/connected. I am but to a lesser degree. I didn't fake the DB process. I really did detach. At that point I wasn't sure I even wanted her anymore. After all, she was a cheater. Who the heck wants a cheater?
Look into the "I need space" statement further without looking like you're looking into it. If there is someone else that changes the strategy so it's important to know.