To achieve a more balanced love between Tristan and Isolde, we can modify their love dynamics with new coefficients:
Tristan's love for Isolde (x): Increase moderately over time (r = 0.2).
Isolde's love for Tristan (y): Increase moderately over time (k = 0.2).
Isolde's love is dampened as Tristan's love grows (j = 0.1).
By using these new coefficients, we can ensure that their love for each other won't spiral out of control during their 21-year lifespan. Unfortunately, I cannot directly provide a plot or numerical solution here, but using these adjusted coefficients, you can plot their balanced love dynamics over time using mathematical software or programming languages.