(a) A person is justified in threatening or using force against another when and to the extent that he or she reasonably believes that such threat or force is necessary to defend himself or herself or a third person against such other´s imminent use of unlawful force; however, except as provided in Code Section 16-3-23, a person is justified in using force which is intended or likely to cause death or great bodily harm only if he or she reasonably believes that such force is necessary to prevent death or great bodily injury to himself or herself or a third person or to prevent the commission of a forcible felony.
(b) A person is not justified in using force under the circumstances specified in subsection (a) of this Code section if he:
(1) Initially provokes the use of force against himself with the intent to use such force as an excuse to inflict bodily harm upon the assailant;
(2) Is attempting to commit, committing, or fleeing after the commission or attempted commission of a felony; or
(3) Was the aggressor or was engaged in a combat by agreement unless he withdraws from the encounter and effectively communicates to such other person his intent to do so and the other, notwithstanding, continues or threatens to continue the use of unlawful force.