Fixing bleached hair oops!!?

Ok so I got some hair lightener and I got a little trigger happy with the spray bottle and long story short I'm a blond now and it is getting darker. is there any way to undo what I've done? Just a bit? Without dying it? I've got the rest of the summer to try but I would really appreciate the help hahaha... FOR THE LOVE OF ALL THAT'S HOLY PLEASE PLEASE!!!!!!