Teaching myself after a 6-year break I hope this is the right sub to ask for assistance. 

I grew up playing the piano (age 4-18) and took basic lessons on a dozen other instruments. I was going to study music composition in college, but got really sick and had to opt for something less physically demanding. Now I’m more or less back to full health and…now I suck at the piano. I don’t have the physical or mental skills I once had. 

It’s a discouraging place to be in, because I have a deep intellectual knowledge of piano, but my body just isn’t in the same place. I’m trying to ask around for advice on where to start. I was playing early advanced music when I fell ill, specifically Sonata in D Major (Haydn, Hob.XVI:37), Prelude and Fugue in Bb Minor (Bach, No. 22, BWV 867), and Nocturne (Field, No. 5).

Any tips on an entry point back into music? Do I just need to whip out Faber books and start from scratch?