It is not possible to feel anger/frustration/fear/guilt AND Joy/optimism/happiness at the same time. So, if you move yourself up the emotional scale and feel joy, anger/frustration is gone.
HOWEVER, if there are negative dominant thoughts that don't allow joy to surface, then they need to be worked with directly. A new perspective of those negative thoughts/beliefs must be held before moving upwards.
Look at my other posts on this forum about the use of Byron Katie's work. That is one way of dissolving negativity.