What should I do about my thoughts that incessantly remember a person despite their absence and their advice that Allah Almighty is most worthy of remembrance?

It is God's right upon His servants that they remember Him, thank Him, and worship Him. However much a servant remembers, thanks, and worships, it is little in comparison to God's right and does not equate to the least blessing God has bestowed upon him. The servant should reflect upon God's Most Beautiful Names and Exalted Attributes so that His love may overcome his heart, and he may find pleasure in His worship and remembrance, and occupy himself with what is most beneficial.