I agree that vitamins are worth trying, especially vitamin D since you are in Sweden. You would not want to take a high dose for a long period of time (months) without getting your blood levels checked, but you cannot harm yourself by trying a high dose (5,000 IU / day) for a couple of weeks to see if you notice any difference.

I take a huge bunch of fish oil every day and if I don't, if I stop for even a few days, I start getting both depressed and anxious. For me, omega-3's are crucial. Other people swear by B vitamins. Maybe try experimenting?

And, as for being in a bit of a rut in therapy (as I recall from some previous thread)... Is there anything you feel you do not want to tell your therapist about? Unfortunately I think a good way of making progress is to find something you would never want to tell them, and then... tell them anyway. Not wanting to talk about something can mean there is a lot of emotion around it, so it can be some of the most useful stuff.