Dude, you're a 5. You got some personal stuff going on at home and you're 16 years old. Despite what most 16 year olds think, they are all dorks in one way or another. Even the ones that look cool from the outside secretly think of themselves as dorks.
ALMOST NOBODY IS COOL AT 16.
And the one or two that are, you don't know them.
And while I agree that you shouldn't care what other people think of you, I also know that telling a teenager not to worry what other people think of them is like trying to watch TV without seeing a "Law & Order" rerun. You know that you should be able to do it and yet, it just keeps popping up!
You can only be as cool as you are right now. A month from now, you might be cooler. And a month after that, maybe less cool.
Just be the best person you can be in the circumstances of any given moment. Beyond that, not much more you can do.