HI there Sheesh and welcome to the forums!
The lovely SophiaM mentioned someone may give you words of wisdom - I'm not all all sure I can do that, but here are a few thoughts anyway.
So you are not sad, not happy but can't feel anything is important or worth doing. I thinks heaps of us feel like that from time to time. A kind of 'can't be bothered' feeling. I have achieved quite a lot in my life yet still get days like that so don't stress out thinking you are the only one!
I have found a couple of things help - one is a daily routine that trains you mind in not only starting, but moving from one thing onto another each day. The second is an activity that generates goals for your mind to think about, even subconsciously. Can be things like a sporting group, book club, activity group like 'MeetUp', learning a musical instrument, daily exercise like walking or a bike ride.
All those things have a kind of built in goal that may help you to think that it's worthwhile getting better at it.
Anyway, I hope these thoughts help a little bit and you feel like doing a little more soon.
Kind regards, The Bro