I'm 26m and it feels like I have been on the wrong path the majority of my life
Is there a reason that you feel you are on the wrong path in life?
I have been in a crippling depression for the majority of my life
It is okay to question how your life has been.  There are always opportunities to change, too.
I have been trying to achieve success or just not be depressed for the rest of my life
You honestly might just need to talk to someone about how you are feeling. It is normal to question you life decisions, but you should not let it consume you.