I told Allah that I will not play video games anymore, but I feel if I play in a limited manner it will help in stress reduction. Can I take back my words to Allah?
You can not take back your promise to Allah (SWT) as far as you are able to fulfill it even with reasonable difficulty. If you don't fulfill your promise to Allah, it will a sinful act, and you must face a heavy Kaffara which is called Kaffara of breaking the promise كفارة العهد which is feeding sixty poor believers.
Wassalam.