I call this the burnout, this comes with depression for alot of people. It's like one moment we are fine, not great but not bad so we are functioning then boom it hits from left field. We suddenly feel overstimulated or overwhelmed with sadness or numbness just like someone hit a kill switch without warning. Sometimes it's like a feeling of shock as you didn't see it coming, what the hell just happened. But at the same time you feel unable to vocalise what your feeling especially to loved ones near you that pick up on it. If you dont understand it how can you explain it to them? Then you see them feel hopeless and just want to help and now it's making you feel worse or guilty on top of everything. What I find helpful is talking with those that want to help about the struggles of the "kill switch" and who when I'm there I can't explain very well and alot of times go nonverbal because the feelings are that overwhelming. I find alot of things can help: if you are with your partner have them snuggle you (neither of you have to talk and if your not forced to talk it is a bit more easy for this), if you like them playing with your hair let them. If you dont want to be touched: listen to some favorite music while relaxing, darken a room and just exist for awhile, no stress or expectations. You can shower or soak in a tub while listening to a audio book or music. You can lay down and just breathe for awhile. You can call a friend to stay in call with you, you can go cry and/or talk to yourself or pretend someone is there and express yourself. Watch that TV show you've been putting off or your favorite movies. Let yourself know it's okay to be this way and your brain can only function so far. It can be that much worse when out in public or in school etc as you can't escape or really step out. I use to go to the bathroom to cry or just take a breather reminding myself my room will be waiting for my retreat. I use to decorate my ceiling with glowing stars, sayings I liked, music verses, pictures that sparked different emotions. Sometimes it's just nice to let yourself exist in these moments and validate yourself.