Start by figuring out what your insecurities are. Write them down on a piece of paper so you can see them in black and white, then go through them and think about where they come from and what beliefs go with them.
Looking at those insecurities can you change your perspective and view them in a loving way? Approaching them with kindness, write down a thought that challenges your insecure beliefs. From these, find affirmations you can use to shift your mindset.
If you’re going to compare then do so against your past self, not those you see around you. Instead of seeing others as competition remember that they’re just like you- they have both strengths and weaknesses. Challenge yourself to focus on your progress rather than your destination.