I notice that when I see a beautiful woman, I am fixated by her beauty. It's like I don't think clearly then. How do I overcome this? I know in my head that I should be playful and funny, but instead I am serious and outcome based, and as a result, she isn't interested in me.
Catch yourself in the act and bring yourself back to reality. The hotter she is, the slower you should move because you know it's harder to think straight.
You know nothing about her aside from her looks. If looks are the only thing that matters you can just go get a hooker. You asking this means you want more, which is good!
What ELSE do you want? Believe and own that you deserve looks AND a pleasant demeanor, and someone that excites you with their thoughts, their hobbies, their goals, etc. 90% of what you want is not based on looks, and you'll only find them out by simply chatting and spending time together.
She is simply a person you find interesting until you qualify her as something more, and you owe it to yourself to not BS yourself if something incompatible surfaces.
You need to own that you are worthy of more than a tight body. Worthy regardless of external validation. The easiest way to develop that self worth is by sitting in discomfort (going solo, working out, abstaining from distractions, etc).
The goal isn't to perform calmness, it's to put in the work for it to manifest naturally. Any quick fix will be short lived. The real thing will come, but it will take you having faith in the process of self mastery.