From what I gather of your descriptions of your feelings it sounds like you are quite depressed. I haven't caught up on your thread so please enlighten me, are you on ADs or anything like that? Do you see a IC?
I think it might be helpful to consider meds.
I can personally relate to some of your feelings. I really have trouble articulating myself in an intelligent way. I feel like I'm stumbling on a wing and a prayer when I create a sentence and it may or may not be relevant to the current conversation. LOL Making a point is HARD for me lately, too. I have it in my head but getting it out my mouth or through my fingers to type is a struggle.
A while back I was quite depressed and I can remember the strength it took for me to get on medication for it. Just a few days after starting I notice that the color of the light from the sun was a different color and that's how I knew I was REALLY depressed. It changed everything for me, for the better.
This roller coaster of BD and separation is just a breeding ground for depression but one of the basic fundamentals in DB is to take care of yourself WELL. Sometimes it needs to be forced to get up off the couch and do something we don't want to do only to realize we needed desperately to do it.
I want to encourage you to seek the help you need.