Hi,
Firstly, please relax. Why do you have to feel worried, tricked, angry, betrayed? Please be glad that your husband opened up to you and said you the truth now. It is still fine for someone to not tell their problems to their spouses.
I appreciate your husband of having come out of this and sharing it with you openly. You must appreciate it as well.
You have lived a happy life with your husband these long years. In my opinion, the
depression was way too small to have been identified by you all these years. I do not think your husband was hiding it either. It was just a minor part of depression, everyone gets depressed occasionally, and it is considered normal.
I do not think you were living in a dream world; you lived the reality.
What to do about this? - Your husband needs a few sessions with a
psychiatrist to assess and evaluate him. If need be he could be started on anti- depressive medicines.
More than anything, your husband need you besides him and that is the reason for his confession to you. Please help him get back to normal life.
I wish you both good health. Take care!