It seems you have low self esteem, there can be many reasons like Unhappy childhood or Poor academic performance or On going stressful life event such as relationship breakdown or financial trouble or can be any other.
Next Steps
try to address the issue first, for help you can consult psychiatrist or psychologist.
Health Tips
Use positive affirmations correctly.
Identify your competencies and develop them.
Learn to accept compliments.
Eliminate self-criticism and introduce self-compassion.
Affirm your real worth.