I'm 64 now. Is there still hope that my personality will change?

When I get older ... There is evidence that personality becomes increasingly stable through adolescence. And, despite all the dramatic life changes of young adulthood, personality remains remarkably stable. But even with this relative stability, personality appears to continue developing throughout adulthood, but, alas only modestly after about age 50. So, there is hope for modest personality change when you're 64.
Motivation? You are likely to modify or change your personality only if you are motivated to do this and set fort the committment to do so. Change is usually motivated by pain.