It is always advisable to save private key,seed or other unlocking file or probably write them down in a diary that you can easily access at any point in time because of cases like that. But since you did none of this, you might be unable to access you information on that particular wallet again.
Writing it on a diary will be a good idea but be sure that no one in your family do know what is a wallet seed.If it does then its still risky when someone gets that dairy.There are lots of ways its up to you won idea as long you can keep it.
this is a position that is not wearing for you, and there is no way out if you do not have a backup, for the future you should have to make double backups, on the phone, the notepad or even in the emails let it really safe
We should have this kind of habit where we should not only focus on having a single back-up and its much better to have lots as long you do know how to keep them safe.Once the other one would be lost you still have other backup as well.Chances of losing funds is less.