I'll second the GDP suggestion. I've noticed quite a few other purples and purple crosses reduce anxiety as well.
Lots of stuff in the blueberry line of genetics is good as well, but is often a bit sedative.
Northern Lights is quite calming, but is heavier on the sedative side. Very appropriate for evening toke.
Is East Coast Sour Diesel available in seed? I dunno... but that one's really good too, though also a bit on the heavy sedative side as well.
Probably my all time favorite calm down strain is Herijuana. Heavy sedative medicine.
I don't know how your metabolism will react, but for a bit more sativa influence (better for daytime) mine agrees with things like: Kali Mist and Super Silver Haze or maybe Satori.