it does sound a bit more like emotional withdrawal because letting go of something doesn't tend to leave you feeling numb on the outside. letting go usually feels quite peaceful to me, as if a burden has been lifted.

don't beat yourself up though for withdrawing a bit. you probably just need a little space to regain some balance. then, you can get back out there. it sounds like you are doing better than in the past with feeling good on the inside whereas before you didn't.