There are so many flavors of depression. Based on your description of long periods with and without mood symptoms I wonder if it's bipolar disorder only the depressed type without mania? Could even be mixed features. I am not a psychiatrist but I think you might consider seeing one for a thorough assessment if you're able.

Maybe you're just prone to depression like myself. Don't go inwards, just take it a day at a time and enjoy the time you have with your husband.
You're probably just stressed which is the cause of the anxiety