Your beginning and end coordinates should be in 4 fields not 2
You will have to add 4 new fields, xfrom, yfrom, xto, yto decimal type.
Then you need to do field calculations
float(!Begin!.split(",")[0]) # for yfrom
float(!Begin!.split(",")[1]) # for xfrom
float(!End!.split(",")[0]) # for yto
float(!End!.split(",")[1]) # for xto
Then proceed from there. (Sort of thrown into the deep end on this I suspect... make sure you thank the person that gave you the data... suggest that they make the table gis friendly in the future 😉 )
... sort of retired...