Push something to the back of your mind
Definition 1 of 1
Pro Tip 1/3Emotional distancing
Using this phrase often indicates emotional distancing from a distressing thought or memory. 
He had to push the argument with his friend to the back of his mind to focus on work.
Pro Tip 2/3Temporary forgetfulness
This phrase suggests a temporary avoidance, not a permanent solution to a problem or feeling. 
During exams, I push all my troubles to the back of my mind.
Pro Tip 3/3Not literal
It's metaphorical, meaning they're not actually moving something physical to a different place. 
It's hard, but I try to push those doubts to the back of my mind.