This is dependant on the seriousness of one’s anger and aggression. If it is very serious, then the person may need counseling. Krsna consciousness cannot resolve psychiatric or psychological problems. By chanting the Hare Krsna Mahamantra, one becomes purified, and eventually, both psychological and psychiatric problems can disappear. But it is important to remember however that people who are intensely affected by such problems, whether it be anger or depression or something else that falls into such a category, it requires proper attention and time to heal. So it is best in such instances for people to seek professional help. This is the reality, even though there is a lot of shame around that, which is very unfortunate.
Anger is a big problem and can spoil many things. This is the very nature of anger; it wants to break; it wants to destroy! So people who have an anger problem tend to destroy their own lives as well as the lives of people around them. So this is not good. But this is just a normal part of life as we are not perfect.
We are all under the influence of the six enemies of the mind – kāma (lust), krodha (anger), lobha (greed), moha (illusion), mada (pride or madness or foolishness) and mātsarya (envy). These weaknesses will be there in everyone in this world – your spouse, your children, your neighbors, your colleagues, everyone and everywhere. Srila Bhaktisiddhanta Saraswati Thakura explains that these six enemies are always attacking us like the bugs buzzing around our head. They are always present in this world and we cannot escape them.
So what are we going to do about that? It is not that, “Oh some people have these problems, but I do not.” No, if you think you do not have these problems, then you are deeply having one of them, illusion. So as devotees, or as aspiring devotees, there must be some willingness to change. Being a Vaishnava does not just mean “From now on, I promise to chant sixteen rounds and follow the four regulative principles.” That is perfect, but not exactly all we need to do. We need to go deeper and say, “From now on, I am ready to change. I am ready to actually change my heart and overcome my own shortcomings.” I understand that this is not an easy process, but it is certainly required to advance in Krsna consciousness.