What happens when I cancel my Adobe Stock subscription? Will I loose the remaining assets/credits?
By canceling your Adobe Stock subscription, you lose access to any unused licenses.
@Marianne-Deiters correctly states, that you will lose all remaining unused credits, but licensed items will stay at your disposal and may be used according to the licensing terms, and can even be downloaded (again) after the cancel. This is true, except if the asset gets deleted from the stock database because of an issue with the asset or when the asset creator deletes the asset. I recommend you store a local copy of the asset in all circumstances.
I am tired of being billed I want to cancel
It is often best to cancel in your 12th month, just before auto renewal, to avoid the cancellation fee. Though it's always cheaper to just pay the fee. You will lose credits, and should make sure you have downloaded every asset you purchased.
use lose unused quota. It is a good practice to download assets locally because contributors can choose to remove their files from Adobe Stock which will prevent the files from being downloaded later.