Hi Shanti:
No need to rush into yoni chin pump. It is a tool for energy cultivation that is useful when we are pretty far down the road. Regular chin pump is a high octane practice, as many of us know. Adding yoni to it makes it much more powerful, like rocketship powerful. For those who feel stable in
all of their practices and wish to try it, just do one or two retentions with yoni as part of the normal chin pump session and see how it feels in daily activity. Then adjust accordingly. Self-pacing.
If I had a dollar for every time I got lost in samyama, we could give AYP books away to everyone.
Just easily come back to the practice when you realize you are off it. It is purification you are going through, a natural part of the process. That is good! If time runs short and you have to go, then it is okay not to finish the sutras. There is always next time. Just be sure to take some rest before getting up.
Like everything else, samyama will vary over time according to the cycles of purification that are going on. So, we self-pace that as necessary too.
In the case of getting lost a lot, maybe put a time limit that you are comfortable with, and then stop. It will come back together as the obstructions clear out. If there is no discomfort in activity after a long samyama session from getting lost a lot, then let it take as long as it wants to, or for as long as you have time for. Your choice.
The guru is in you.