Only thing that is truly only accessible by you is your memory, so if you forget everything then there is no way to do it without trusting someone else.
Not to mention that you wouldn't even remember you had a wallet in the first place.
You can't not trust yourself and others at the same time, there is no one with any access to the wallet then.
If one part of the wallet is lost, all is lost. If a group of people have all the parts of the wallet, then they and only them can use it. If you are part of the group, you can't forget your part, if you are not, then you have to trust the group.

I lost many accounts due to forgetting my passwords, but there is no other way except giving someone else access or have another way of access.

You need to trust yourself and if you have a backup, for yourself or others, then figure out a place that you can always protect while you are alive. When you are dead, they can take it from you. If you are afraid that someone will kill you for it, then you need to only be able to get it by your memory.

You can't have both perfect security and perfect availability. If you care more about security, then carry full responsibility. If you care more about it not getting lost, then you have to trust someone in one way or the other.