I'll spell it out. You need a purpose that transcends yourself, your individual experiences and material possessions. Hiking and holidays ain't gonna cut it my brother. You know this because you've run that experiment and you are still left with a hole in your soul that you can't stand.
You need children. You don't want them (yet) but you sure as hell need them. Almost everyone does. It's not your fault that it's difficult to come to terms with this, you have been programmed to think that they're optional, when they really aren't for the vast, vast majority. What will be your fault, is if you continue to ignore the blaring "meaning" alarm bells that your soul is sounding, continue to attempt to fill the hole inside you with frankly hollow items, only to end up feeling the same a couple more decades down the line. Older, lonelier, with less energy and less options. Yes, you may not believe yourself to be "fit" for it as you are, and this will mean you will have to change. This is the entire point. Think about the kind of person you will have to become to be a good parent. Truly, the greatest value in life is not in what you possess, it is in what you become.