I need help with my hair, should I go back to just blonde?

If you want to be more natural, then you should go blonde on the top again. It would be far less work that what you've described. if you really like having black in the lower layers of your hair, then keep it. If you feel like you would like change (and perhaps still want to look natural) then you could always opt for a darker shade of blonde than what's on top, or a nice chocolate brown. it would give it dimension and look very pretty.