Hi Alvin:
Irritability or other excessive emotions in activity can be an overflow of purification from deep meditation or other practices.
The first thing to be sure of is that you are taking at least a few minutes "coming out" of meditation, with no intention to pick up the mantra during that time -- just easily resting. If there has been some roughness in the session (or even if not) it is good to lie down for 5-10 minutes at the end. Not resting enough at the end of meditation is the most common cause of overflow of unwinding purification into activity, which can manifest with some emotions in the way you described.
Less common is a sensitivity to meditation in the individual. If irritability continues in activity even with good rest at the end of meditation, then sensitivity to meditation may be the cause. The way to find out and deal with it is by scaling back the time of meditation a bit (5-10 minutes) and see if that helps. If it does and the emotions smooth out, then we can try inching back up with meditation time when we are feeling better to fine tune our time to the right amount for ongoing smooth purification.
Of course, meditating for more than 20 minutes twice per day is asking for irritability, for just about anyone. That goes without saying, yes?
There can be many ups and downs along the path of inner purification, and we can navigate them by regulating our practice a bit up and down along the way, much like driving a car along a winding road and adjusting our speed to match the varying conditions along the way. This is the art of self-pacing.
Finally, inner energy excesses can also happen by adding other practices, and/or by doubling up on practices, especially when using several pranayama methods in the same session or day. Of course, I cannot speak to all the other practices you may be inclined to try in addition to AYP. These will be your individual research. Let us know of your discoveries! But do keep in mind that beginning stage is not necessarily the best time to be doing research on the effects of diverse practices. Better to get a foundation of inner silence underneath with deep meditation, and then you can tolerate much better the inevitable excesses one is bound to encounter when doing research – trying new things. That goes for taking on new practices within AYP too.
It is good to be aware that there is only so much purification our nervous system can handle comfortably on any given day, and ongoing irritability or other energy upheavals are the common symptoms of continually overdoing in some area of our practice.
Other than that, it sounds like you are having some good benefits already in your life. As you stabilize your routine it will become even better!
The guru is in you.