People often ask how to stop obsessing about something.
Trouble is, if you have an obsession, you cannot, at least not durably.
The obsession must be removed at root, for a person to stop performing it mentally.
What is an obsession?
Obsessions always centre around the delusion that something is wrong and something else will fix it.
A thing.
Comfort.
Reputation.
Praise.
Or the fear of their opposite:
Deprivation.
Pain.
Notoriety.
Blame.
Unless the illusory nature of all of these commodities and evils is understood at heart, obsessions will continue to arise and slosh around, finding their most suitable object onto which to project.
The solution is total reliance on God and total renunciation of false idols.
There is no other solution.
Read Anthony de Mello, Lama Zopa Rinpoche, and the book of Ecclesiastes.