Some blue days can turn into blue months and blue years.
That can be all right.
As long as you can see that colors can change.
People change. People grow and bend and sometimes they break.
You can only heal yourself, though.
You can love someone deeply and truly and madly and they will never change.
I think the trick is to love yourself that way.
You will change.
Mourn the loss of your former self and move on.