This is so common: you are not alone! I would suggest Menopause Support, which contains soy and magnesium. Soy is known to help with the common symptoms of the menopause including memory, and magnesium is needed for mood, relaxation, sleep etc. It does take a few weeks to start showing benefit, so you can use Concentration Essence as well for the first few week. This can be taken when needed, so you can have it to hand at work. You can get these from most health shops or direct from us at www.avogel.co.uk.
Acupuncture can often be really effective for this set of symptoms, so it is worth looking into. 30 min relaxation every day is a must - research has shown that daily relaxation can reduce stress very quickly. You can get lovely relaxation CDs/downloads from Amazon.