I get stressed at times but as a highly sensitive person, getting overwhelmed with stimulation can increase the stress. I've noticed that often when I'm a bit stressed, overwhelmed or feeling a little flat in my mood I do the general HSP thing and hide away to recharge.
I have some wonderful friends who remind me that they are there if I want to talk about what's on my mind, an ever present ear for me to bend but I rarely accept the offer - as kind and generous as it is.
When I'm in any of the above mentioned states, it's better for me to just recharge on my own in my private space. I may lurk a little online to keep up with what is going on but I'm not really up for much communication at all. I prefer to think about whatever is troubling me, write about it in my journal if I need to get it out of my system.
Sometimes if I share my frustrations with my friends on Facebook, this is often my way of just letting them know what's happening so when I do inevitably go quiet they understand (hopefully). Many take these as invitations for solutions or advice but I rarely post for those things and I know that the advice is well-meaning. I ask if I want advice or help finding a solution to a problem. I don't particularly like advice dropped on me without an invitation because quite often people don't see things from a HSP perspective so while it might not be bad advice, it's not necessarily going to work for a HSP.
So when I need my "down time" for whatever reason, I withdraw to what I call my Hidey Hole and do what works for me, during which I do a lot of thinking about whatever is on my mind as well as other things and put it into some sort of perspective that helps me. Only I can do that, I take responsibility for myself and find my own solutions.