Dear sister, beloved child of shakti,
for queries related to maa pitambara sadhna, i recommend you to take"Baglamukhi diksha".
Yes, HLEEM indeed is cursed, that is why agni beej 'r' is added. Maa Baglamukhi beej mantra is "HLREEM".
Sit straight while doing sadhna. For improving your concentration chant"STREEM" beej mantra, it will create a mental bridge between you and the deity.
In case the rosary falls, pick it up, touch your right ear with your right palm, and start all over again.
After completing the sadhna, to beg forgiveness from Maa baglamukhi for any mistakes, read "APARADH KSHMAPAN STOTRAM".