Creating two dodged barplots stacked on top of each other for my two variables

Say that I have a data frame that looks like this...

#create dataframe
rG_activity <- c("0.368", "0.468", "0.427", "0.091")
rG_activity_error_intervals <- c("(0.468, 0.268)", "(0.568, 0.368)", "(0.527, 0.327)", "(1.091, -0.909)")
rG_task_persistence <- c("-0.462", "-0.345", "-0.291", "-1.062")
rG_task_persistence_error_intervals <- c("(-0.562, -0.362)", "(-0.445, -0.245)", "(-0.391, -0.191)", "(-2.091, -0.062)")
rE_activity <- c("-0.162", "-0.245", "-0.129", "-0.462")
rE_activity_error_intervals <- c("(-0.262, -0.062)", "(-0.345, -0.145)", "(-0.229, -0.029)", "(-0.562, -0.362)")
rE_task_persistence <- c("-0.362", "-0.245", "-0.191", "-0.162")
rE_task_persistence_error_intervals <- c("(-0.462, -0.262)", "(-0.345, -0.145)", "(-0.291, -0.091)", "(-0.262, -0.062)")
age <- c("30", "24", "18", "12")
df <- data.frame(age, rG_activity, rG_activity_error_intervals, rG_task_persistence, rG_task_persistence_error_intervals, rE_activity, rE_activity_error_intervals, rE_task_persistence, rE_task_persistence_error_intervals)

  age rG_activity rG_activity_error_intervals rG_task_persistence rG_task_persistence_error_intervals rE_activity rE_activity_error_intervals
1  30       0.368              (0.468, 0.268)              -0.462                    (-0.562, -0.362)      -0.162            (-0.262, -0.062)
2  24       0.468              (0.568, 0.368)              -0.345                    (-0.445, -0.245)      -0.245            (-0.345, -0.145)
3  18       0.427              (0.527, 0.327)              -0.291                    (-0.391, -0.191)      -0.129            (-0.229, -0.029)
4  12       0.091             (1.091, -0.909)              -1.062                    (-2.091, -0.062)      -0.462            (-0.562, -0.362)
  rE_task_persistence rE_task_persistence_error_intervals
1              -0.362                    (-0.462, -0.262)
2              -0.245                    (-0.345, -0.145)
3              -0.191                    (-0.291, -0.091)
4              -0.162                    (-0.262, -0.062)

The two main variables of interest are "activity" and "task_persistence". For instance, for activity, I have rG_activity and rE_activity for each age (12, 18, 24, 30), same for task_persistence, along with the respective error intervals for each age. I would like to create two dodged bar plots for "activity" and "task_persistence" stacked on top of each other just like my example below (which includes the error intervals and the legend at the bottom). (note: the values on the barplot below do not reflect the values in my sample data above). Would appreciate any help.