Whom should I worship exactly?

Namaskar I am 33 years old & from childhood I had fascination for the shivling. I loved doing abhishek on the shivling & sitting in Shiv temple. Because of my Grandmother I started doing Raam naam japa at 17. After a few years, I was distracted & everything stopped. I came back to Hindu spirituality & have rediscovered Shiva. I am going through the final phase of my Sade Sati (Vrishchik rashi). I am doing Om Namah Shivay japa & Shivling puja. I heard Mr. Rajarshi Nandy say on YouTube that lord Shiva does not respond faster & You have to worship him in Bhairava form as Bhairava responds faster & also helps get rid of Graha dosh/Sade saati. But, ever since I have started worshipping Shivling, I have seen some things that I can't share here. I am getting confused by the statement of a few online gurus who say Bhairava worship will help you achieve spiritual goals faster & also to get rid of Grah doshas. Is it true? Does Shiva take many births to respond? Please guide.