Going to receive Guru Diksha soon. Advice plzzz

So I was experiencing a blissful state in meditation from past few years and I didn't understood what it really is and I didn't had any right person to talk to about it. I was also eager to take that forward. When I was experiencing a tremendous lust which I couldn't handle, so I went to seek advice from my astrologer and he advised me that beyond this I need a Guru-Diksha.
So he made me contact his Guru and going to receive a Guru-Diksha next month. Please advice me something so that I can utilize my diksha to the fullest. Also, ppl who are already dikshit and doing japa of Guru mantra, plzz share yr experience abt how did the Guru mantra transformed you and in what time.