Yes, seeing happy couples is a downer, isn't it? I know that you are feeling 'done' right now, but it is important for you to get going with the GAL work at full tilt the more acting out he does. The books, school, outings with DDs and friends, all this will help you, Jo.
The furniture thing is interesting. My W is doing somethign similar. I appreciate the need to do s/t different, especially if X chose it for you. My W is trying to get me to buy our furniture from her (not going to happen ) so that she can get all new things. I understand the bed change.
This R stuff is rough, Jo. Keep looking for the break in the clouds. The pub outings might be a fun way to enjoy convos and to feel/be seen.
As a man, I ask you to not feel rejected or less than due to the presence of OW2. This is a blatant sign of weakness in X, not a reflection of you. Hold onto that.