How do you see yourself vs the way others see you?
There is often a huge difference between looking out from somewhere, than looking in. The ‘you’ you see in the mirror is different than the ‘you’ seen by the people around you: you are going to do and say things that you aren't fully aware of, sometimes for the better sometimes for the worse.
The worst thing you can do (in my opinion) is isolate yourself, because then you have only yourself to reference yourself. Insecurities will magnify themselves whether they are true or just constructs of your own overactive mind.
Compare a rabbit to a rabbit and you will draw many similar conclusions. Now imagine if the only animal you have ever seen is a rabbit...yeah life gets pretty boring after all those rabbits.
Many of the most profound and emotionally meaningful realizations about myself have come from others. Having friends who ‘get’ you and accept you for your flaws as well as your merits is really important.