Memorize. Not only does memorization help create synapses in your brain, as you memorize melodies and scales you will begin to develop a better ear for individual notes and solos.
Yes, memorization is going to be more difficult at the age of 60 than it was at 16, 26 or even 36.
Stay with it. It’ll come.
Think of other things people come to later in life and, over time, master. RVing, fly-fishing, birding, baking and cooking can seem overwhelming at first. Yet, with repeated practice knowledge that once had to be constantly reviewed gradually becomes ingrained until various water and electrical hook-ups are done without hesitation, knots are tied easily by rote, a glance reveals the difference between a crossbill and a grosbeak, and a properly seasoned dish becomes almost instinctive.
Even if you don’t get everything you play memorized perfectly, you’re still building music connections in your brain. And you’ll probably surprise yourself. The more music you memorize, the easier additional memorization becomes.