In order to be a good rider you must have good flexibility, especially through your hips. If your hip flexors are too tight you will struggle to hold your leg in the correct spot. There is no miracle cure.
You must put the effort in and start stretching everyday.
Put aside 10 minutes everyday to stretch.
And in no time you will see your riding starting to improve with the added flexibility in you.
There are so many videos on YouTube by professionals that will give you great advice and step by step instructions. You have no excuses, your riding success is at your finger tips!