There are situations which leads to anxiety, anxiousness, often these situations are based upon perpetual memory (which is, "if this happens then that will happen" and then the anxiety creeps in, because of self conceived resultants) leading the individual to anguish and dismay about the thing which isn’t there in present, but is speculated to happen.
These kinds of things lead to mood swings, change of the mood all of a sudden, by the input of some information supplied/ injected by someone, who in your proposition memory is a “truth bearer”.
According to the vedas, this dysfunction (mood swing), is due to blockage in the sacral chakra (the chakra just below your navel), and is more than often corresponded with indigestion or sleep disorders or both of them.
Physically this can be seen with feeble abdominal muscles in lower abdominal area, often making it less or hyper sensitive (like presence of briefs/belt/pant marks in semi circular manner, more intense where pelvis bone area).
There are many methods enshrined in the vedas of dealing with this dysfunction, but the author would like to submit, the more easy way for the beginners to take control of their lives (as life is driven by moods and emotions), and start this by using the most prominent ethos, which is “breath”.
The prudence of breath is synonym to life, and by tailoring the way the breath is inhaled and exhaled can lead favourable changes in the manifestation of life (the author doesn’t refer this being a bridge with unknown force, GOD. But is only referring how to refine thyself and hence the societal life).
Take a deep breath inside, hold it in your chest and then bring back the breath to your nostrils and then again suck it back and bring it to your chest, repeat.
The quantum of the breath inhaled, the duration of the holding of the breath, is individual based (initially) and then should be enhanced, and during the course, when you will be more observant about the changes which this exercise is bringing, you will feel how to change of sounds within (tinnitus) would more soothing, then being a irritating “pulse”.
Exercising this is likely you to have lesser mood swings, which would make your more observant about the situation, which would result in you being a “protagonist” of your own life, than being driven by the emotions.
Psychology too recognises this, and rightfully ranks it as a dysfunction, leading the individual to a state of “astray," and links it to some impairments in the medial temporal lobe ( mid section in your brain).