Your condition sounds a lot like mine - hypomania, come down, get angry. I take Depakote and it has worked very well for me. It's actually a medication prescribed for seizure disorders but they found it to have dual efficacy when it comes to BP or BPD.

I still get angry but my outbursts and how I act on the anger have tapered considerably.

It took a while for the meds to work - a month or so. I went from 500 to 1000 to 1500 where I am now. I was on 750/750 but I was nodding off in the middle of the day so my p-doc changed it to 500/500/500 and it's been gold for me.