If you're with someone and you dont't feel good enough, you need to think again. 
There are so many people in this world, there are so many other people around you, around them. 
And they chose you. 
You're not the only person that they have met, you're not the only person that they have been friends with. 
You're not the only person that they have liked. 
But they chose you. 
You mat not be the hottest person that they have ever met, but in their eyes, you're something amazing. 
You're something special and that is why they chose you. 
Never doubt yourself. Ever. 
If they didn't see something special in you, then they wouldn't be with you. 
Accept the fact that you are good enough.