Psychological effects of menopause.

My wife has recently started menopause (two months) and her personality has changed drastically. She moves between very nice and extremely angry if something makes her mad. She does not let go of the anger and it's creating a real problem in our relationship.

Is this normal and if so (or not) what can be done?

Many women experience symptoms of the menopause and irregular periods for several years up to menopause itself and every woman experiences it differently. Many hardly notice the change except the period becoming irregular, and some other suffer every single symptom.
Generally, the symptoms of menopause are hot flushes and sweating, sleep disturbance, psychological changes such as depression, tiredness, headaches, forgetfulness and mood swings as well. This can be very irritating and distressing for both you and your wife as I believe she is not comfortable with this condition herself! You should help your wife and you go through this period together. She would surely appreciate that!
Also, there is the medical treatment available, would she consider taking some therapy? She can always consult her doctor about Hormone Replacement Therapy but it hasn’t been recommended lately due to cancer-risks. I would suggest acupuncture!