Jazzmammal's advice is excellent. I need to follow his advice and it is on my list.

For what it's worth, I have the same problem you do. I use lead sheets printed from BIAB containing chords and the melody line. I perform mostly jazz and bossa standards. My background is classical (B.A. in Music) but made the switch to jazz a few years ago. No doubt I'm using the music as a crutch but I still do it.

My 'talent' has always been harmony and not melody. What I have found is that most songs I play have pretty much the same structure AABA. The songs typically have a temporary simple modulation returning 'home' in the last phrase. There are also common chord progressions (ii-V-I) that occur in many of those songs. After a while, I started hearing these common progressions allowing me to take my eyes off the music and look at the dancers on the floor. When I solo, I know the chord progressions and improvise based on what notes are available in that chord. I read a jazz book that said if you hit a wrong note, it is usually one note off from the right one. When that happens to me, I just use the wrong note as a passing note and resolve it.

I don't know your theory background but assume your ear must be good after playing for 60 years. Aside from Mammal's advice, I recommend a thorough knowledge of keys, Circle of 5ths. and of course scales.

Now don't do as I do, but do as I say.

R