We don't really have enough info to help you out. Could you ask this with a minimal REPRoducible EXample (reprex)? A reprex makes it much easier for others to understand your issue and figure out how to help.
If you've never heard of a reprex before, you might want to start by reading this FAQ:
an obvious issue even without accessing your data is that there is no relationship between the object d that you load with read.csv() and the subsequent call to hist()