Is there any way for you to watch skilled pianists performing?
There is a lot of stuff that doesn't make sense until you see it done up close, and if you don't have a teacher you may not have anyone to demonstrate.
I sit near any performer who I think plays well, at church or a concert, and watch. What is their posture, the angle of their arms, how does their hand look, does mine look the same or not, etc. There is a lot you can pick up without a formal lesson.