I have been struggling with my mental health recently and in the past have had bad coping mechanisms
Unfortunately I am getting the urge to self harm again and I am trying not too but this is very very hard. To stop myself I have been snapping a rubber band against my wrist instead. Is this okay as it stops me from doing anything else?

If you are suffering from a mental health illness you should see a medical practitioner. As for snapping yourself with a rubber band, as long as it doesn’t mark and make damage, I don’t see a problem with it.