Be unfuckwithable.

Love the person you see in the mirror.
Look at yourself in a mirror and say some genuinely loving things to yourself. You can use simple sentences like “I love you,”; “I care for you,”; “You matter.” Speak to your soul, your true inner self. Understand yourself, your mistakes, and your struggles, and be compassionate.

Appreciate yourself.
Write a thank-you note, thanking yourself for all the valuables in your mind and soul. Mention your personal qualities such as kindness, a sense of humor, reading habits, responsibility, good organization, optimism, etc.

Detach from fear and anxiety.
Put your attention to the present moment so you can detach from fear. Write down what is good now, describe some object in your room, and focus on the rising and falling of your breath. Focusing on the present moment distracts us from many unnecessary fears.

Set self-fueled goals.
Set three goals whose outcomes are dependent on you. One example is a goal to keep a positive mindset, regardless of the circumstances.

Realize you are enough.
Reread your thank-you note from step 2 and use this as a reason to believe that you are enough, deserving, and worthy.

Grow immune to others' criticism.
Write down one critique you are sensitive to and look at it from a fresh perspective.