Zikr & Dua

Proof of reciting prescribed azkaar by the Mashaayikh

Q: There are some specific prescribed Zikr by the Ulema and Mashaykh which are called "Wazifa". These are certain Azkaar of reading a Dua, or Ayah of Quran or the names of Allah for a specific number of times in order to achieve something. 

My question is that, do we have evidences from the Quran, Sunnah and the practice of the Salaf on practicing these prescribed Azkaar? Can you please list them in detail with references.

Not feeling the connection when making dua at the time of tahajjud

Q: Tonight I got up to pray tahajjud and when I started praying it felt like a tahajjud prayer though when I went into Sajda, I didn't feel the connection I thought I would, like I went to Allah in taha while crying and when I started praying all my tears were gone, I wasn't able to cry in my sujood. Does this mean I didn't pray it right?

As I checked that I did my wudu right and covered up my self right though still I feel something was missing.

Adding to that, I'm one day away from my periods and I also thought that the crying part was just from my mood swings which are a symptom of our period coming, because when I stood on the prayer mat all the tears went away.

Moreover, I had weird thoughts during the prayer like I wasn't praying right and had alot of skulls appearing in my thoughts (jinn like thoughts). Please share if there is a problem in this or am I just overthinking?