Heya,
I take epilim (sodium valproate same as you) 800mg. I have bipolar two too and find that I still bob a tiny bit but I like it because I can get a teeny bit happy haha. And I take 3/4 of a 50mg seroquel to sleep and to help with anxiety.
Only side effects were an upset tummy while increasing the dose at the start, and my perfect metabolism was ruined. That said I think I put on 5kg in the first while, but have been on them for a year with no more weight gain than that. I was pretty skinny before from running around being mad though so no biggy.
Epilim didn't get me there 100%, I stayed pretty down but not so acutely For a while but seroquel really helped lift my food. As soon as I sleep I'm ok it seems?
Good luck
Oh yeah I forgot... My concentration was terrible too but has improved slowly by itself, hopefully yours does too?
And taking all the meds at night helped