I know what it's like but the feelings pass and this one will too. The absolute hardest thing about BPD is it's like you have multiple personalitites to a large degree. When you're happy, there's nothing better in the world, you're finally recovering, you won't slip so far again, how did you ever feel "that" way, etc; and when you're down you're suicidal, trapped, lost, nothing will ever feel right again, you'll never recover, etc....and those feelings can come only minutes, hours apart. It's absolutely horrible and I totally relate.
I mention this a lot and probably sound like a broken record, but the only thing that I have found that has helped me at all is mindfulness and meditation. It puts you in the present moment, somewhere we usually aren't....instead we are dwelling somewhere in the past or worrying about what may never happen. It is NOT a quick fix. It is A LOT of work. I have been at it for a year and a half, but if you try it with an open mind and really work at it, I believe that it will give almost all of us some relief.
Two resources:
DBT Self Help. Go to the "Instant Mindfulness" section. These are short guided meditations that have relaxing images and music. Another is
audiodharma.com. It also is filled with short meditations. Don't sit down and attempt to meditate for 20-30 minutes...it's not gonna happen. Try just a minute or two and build from there, plus, you may not "get it" right away. I am very prone to disassociation and the first several months I did it that's what I did...totally numbed out in to my own world.
If you'd like any additional resources, please, Toolesque or anyone, PM me. I really believe in this or I wouldn't be touting it so, and I want all of us to see a little light at the end of the tunnel now and then. I know how hard it is for all of us.