ESA / Limited Capability for work

I have been claiming ESA since  08/03/21. on the 26/01/2022 i had a telephone Assessment for Limited Capability for work. The lady who conducted the call said that i had 3 descriptors each scoring 15 points.  and that i should be put in the category unfit for work, How long do they take to make a decision? and will i receive any backdated payment. I understand that there is a 13 week assessment period from start of claim supposedly to the Assessment, Can someone tell me the rates of payment? thank you in advance i've read a few articles discussions on here and you lot know your stuff