How can I stop being insecure?

By re-exploring your belief system, by being fully present in the moment. Recognizing that you are a consciousness at this instant and that the former or future selves are only illusions. Are you happy now? Are you safe now? Are you healthy now? Are you living with ease now? Is there a threat in sight? Is it rational or irrational? These are questions worth asking.

I sometimes feel insecure myself, but I try to replace my insecurity with gratefulness (plus a bit of ignorance is good too). Why ignorance? One of the reason of insecurity is about pleasing other people. But as a matter of fact, you can't please everyone. Just be yourself and try to think about yourself first before listening to others opinion.

Find all the perfections about yourself, make yourself feel good, dress in clothes that look good to YOU! not anyone else, do things for yourself that make you feel good!

I would try to beat my fears. Step by step and maybe with the help of a friend who knows about your struggles. If you can overcome those fears, you will be more confident. Even if it's hard at the beginning.

I think feeling insecure is a state of mind. As you can be happy, sad, angry,... I think starting a new activity can restart you mood: exciting your 5 senses help you change your mood and over time, it helps greatly. For example: eating or cooking something new, discovering new tastes, starting a new book, listening a new style of music, starting a sport, meditation, yoga... There are plenty of activity to change your state of mind. Moreover you also learn. By learning I mean growing, perceiving things differently, opening your mind. Can you still feel insecure when you are engaged in activity you like ?

Tell a friend about your situation and your friend will always be there to help you and support you.

Surround yourself with good people, people you can trust, and then it goes all with the flow. Tell yourself some optimistic sentences

I don't think being insecure is something you can just turn off. I think the best way to help with your insecurities is tell yourself things that you currently don't believe. Sometimes I look in the mirror and feel ugly but I tell myself five times that I look good and am pretty and it helps my overall outlook.

Believe in yourself. It's a long process, but worth it. Everyone is insecure about something. Hard work and belief is the biggest help. Accept the things you can't change.