
Without knowing more details about both situations it is difficult to advise you as to what will likely happen, but you don't want to simply plea out. Your arrest in Dekalb can definitely affect your probation status in Whitfield. It is possible for the Court to revoke your probation status in Whitfield for violating your probation and getting arrested.
Do not wait until your court date to take action; be proactive and speak with a criminal defense attorney as soon as possible.