It's so tough out there. So many people looking for work, so little jobs. I have completed my schooling, but I don't have my diploma, so I don't get the work because there is SOOOOOOOOOOOOO many people out there who do have a diploma and WORK EXPERIANCE. So yes it svcks you don't have the work experiance, but it imagine how much more tougher it would be to get that job, with no work experiance and NO diploma?
So depending on the job you want, yes you need both. Lots of jobs that don't ask for Collage diplomas, DO ask for Highschool Diplomas though. So just try and get a job you want in your field without a HS diploma and or Collage diploma.