I've found this basic definition of Dīkṣā though I don't know in which scripture it appears -
svarupasambodhadanatmako bhedamayabandha-ksapanalaksanasca sarhskaravisesah
i.e. Dikshā is a particular consecration ceremony for initiation into the higher life, conferring on the initiate the gift of knowing oneself, and casting away the impurity due to the sense of difference that binds oneself.
Going through this definition, it seems one can be initiated by oneself, without physical guru.
So can I initiate myself, if possible how?
Can anyone cite the source & explanation of this verse or answer the esoteric meaning of Dīkṣā citing any good source?.