What will I do if my best friend end our friendship because she said it's awkward? She end it for not a valid reason. She told me to let go. Should I let go or what?

An awkward situation means a person/or the people involved are uncomfortable with one another. When your friend said she wanted to end your friendship, it is likely because she is not comfortable with you. This does not put any blame on you or her. Some people just are not compatible, even if you thought she was a good friend for you. Differences in how people behave with each other may be too opposing that the friendship just can not stay. Unless you truly believe the connection between you two was too strong to break, then try and fix your relationship. If not, then don't fret too much because some friends come and go. Your true friends will care for you no matter what and embrace your good and bad. They will stick with you through anything like family so you should consider whether this friendship is worth fighting for in the end.

I am sorry to hear that. From my point of view, please try to find out whether there is misunderstanding between you. And calm down for a while. Turn friendship never be given up easily. 

My Initial thought is that you should ask why is it awkward? What is the cause of that awkwardness. And if it can be fixed then you should fix it.

And, also, in my opinion if you truly are friends, and in your case best friends, both of you should be more honest or rather frank with each other. :) and resolve all the issues between the two of you.