I don't know how to deal with depression anymore.
I was diagnosed, along with BPD, a major depression when I was 18 years old and now that I'm 25 I feel myself rapidly spiralling down that same well...
I've been feeling more useless and worthless than usual, my anxiety is getting out of hand and I just want to lie in bed and cry. 
Honestly I just want to give up because I know how this works, I hit rock bottom but I manage to swim to the surface and just when I've managed to breathe again and feel at ease, I helplessly drown again. So what's the point of fighting if it never lasts? It's always like this, I know the cycle so well. I've been here so many times before.
Lately I don't even want to see my boyfriend, and I only go out because my mother insists but it does barely anything to improve my mood. I'm just... exhausted.
It has gotten to the point that I don't even mind if they have to "lock me up" in the psychiatric unit again. I haven't tried anything to end my life because I've regretted doing so in the past but the urge to hurt myself is so downright strong that I hate myself for it.
What do you do when you are like this? What gives you the strength to stand up once again?