Pick a song with 3 chords that you know the tune by heart already,,,, and dont THINK about any pattern. Try to just let yourself groove into the feel of the music. That may sound strange, but if you dont learn how to "feel it" you will never experience the freedom of playing.
I had a friend that could play some complex fingerpicking blues,,,, but when it came to strumming he was a beginner,, he couldnt "feel it" and insisted on counting 1&2& etc. He would not give himself the opportunity to try & fail ,, until he achieved his goal.
I never had a strumming problem from the start,, but when I learned to alt thumb pick blues,, I couldnt keep that thumb going and play the higher notes,, I kept at it ,, and believe it or not ,,,,,, the things that seem totally impossible at the start CAN become easy and automatic.
Give yourself some time, any the permission to fail,, and you will suceed. sorry if this sounds like Tony Robbins LOL
Steve