I used to have that, for a long long time.
Then I realised:
All the other animals are doing things right, just by living their lives and doing what comes naturally. They don't need to consciously know the purpose and have a goal, they're fulfilling it already.
I don't see why humans would be any different. We don't know what our purpose/goal is but I'm confident that we're all fulfilling it, whatever it is.
The purpose of life is to live. Just by living, we fulfill our purpose. Life is inherently meaningful, whether you figure it out or not.