Re: Wife wants to be alone? What does that mean?
At minimum, it sounds as though she is missing an emotional connection with you. If she has felt this way for several months or years she may have filled this void with someone at work.
It doesn't necessarily mean an affair, but as Amp said, she may be involved in an emotional affair and not even realize it or consider it wrong.
I do think saying she still loves you and thinks you are a good husband, father, etc. but does not want any physical intimacy is odd. It doesn't mean she's 'getting that elsewhere' but it may mean she is having thoughts about someone else that have pushed her away from you.
Since she started this job, has she spoken of anyone in particular there? That could be another sign.
I know for me I need to feel emotionally close to my husband for the sexual desire to be there so if she has felt disconnected for some time, she may have just reached the point of not wanting to go through the motions.
If she does not want to talk pressing the issue may push her further away, but since she has suggested separation, maybe your approach should be from that angle...I've thought about your request for a separation and I'm struggling with the idea because I don't feel I fully understand your need to be alone. If you are feeling something is missing with us, I'd much rather focus on making changes within our marriage so you are feeling fulfilled.
She may feel she has already tried to get you to open up and feels 'spent' at this point, so the more understanding you are of where she is at the more likely she will open up about it.