Not 1 of you muffukkaz said EDIT:
@10bandz did, salute!
HAPPY BIRTHDAY OP
The others are right: others could have it worse.
But for many people the factual knowledge that others have it worse, doesn't help put things in perspective much.
If you feel bad, you feel bad.
So let's not compare in your case.
Purpose.
That is the only way this down feeling turns around.
A sense of purpose changes everything.
Your porblem may be: I have no clue what I want to do with my life.
Welcome to the club.
But it is ultimately your life and you know you best: there is SOMETHING you'd love doing if you could.
Figure that out and you found a purpose.
Then you need a strategy to meet your goal. I suggest you google: 'Procrastination monkey' and read the few articles on it. Thank me later.
Feel free to DM if you have any questions. Find your purpose and next birthday you'll feel better.
Btw: you're part of the majority of people who during their 20s had time fly by and wake up (almost) 30. Your age means nothing these days, what you have to offer means everything so don't worry.