Babaal, first make sure that's what you have. Manytimes self loathing and inadequateness are hidden under existential crisis. Be true to yourself then you can heal yourself.

If you really have it, then maybe planning would help. Where do you see yourself in 5 years? 10 years? After retirement? Just thinking about them and coming up with some kind of plan would help.
Also, don't stay alone, have some company.