By finding something/someone else to obsess over. Or by trying to understand what is making you obsessive and deal with it in a healthy way.
How to get over an obsession?
Gator is correct. You most likely have an obsessive nature, perhaps turn that obsession to something more beneficial to your health or the environment.
Either way, by swapping out one obsession for another you can still feed your brain that which it needs.
If you Google overcoming an obsession, you will find a number of links with advice for specific obsessions as well as just general ones.
Browse at your leisure