Dear Sravna,
There are two types of breath stopping.
It's called:
1)Antar Kumbhaka( Inner retention)
2)Bahir Kumbhaka( outer retention)
In Inner retention, the breath stops after inhalation.
It stops for sometime till the need to exhale arises.
Advanced yogis experience longer durations.
In Outer retention, breath stops after exhalation...again advanced yogis have longer durations.
For those who are getting into this type of breathing patterns naturally without pranayama practices, this happens on and off..then it goes back to regular patterns then it comes back again to breath retention.
Thats why you had a 6 months gap.
Its perfectly normal.
No one used any technology to alter your patterns.
Part of you has some fixation of being " attacked" by some forces.
This is where I have to let you know that its your health diagnosis which is creating this waves of suspicion.
At the same time I wont deny that you are also going through a spiritual awakening.
Going to sound a little Native American here.
All of us have Two Wolves..a good and a bad.
In your case the Good Wolf is the Spiritual Awakening.
The Bad Wolf is the medical history casting its effect on your mind.
So which wolf wins?
The one you feed!
Stop feeding the bad wolf please, then you would bloom.
Its my sincere advise to you.