Counselling can help you to help jealous wife

Ever since my wife lost her job she has become depressed and socially isolated. 

I encouraged her to go out and make new friends but she wouldn’t, so I gave up. Now she has become obsessed that I might be having an affair (I’m not) and questions me exhaustively — sometimes becoming very upset — every time I come home from work.

I find it exhausting and can’t cope with her jealousy any longer. What can I do to get back the woman I married?