Can you give me some advice on my bladder issue? How long after breastfeeding ends is it abnormal to have incontinence?

See your PCP. It is likely that your incontinence may have been related to your labor and delivery rather than breastfeeding. It is best to see your pcp re this problem.
It should not matter. I think your bladder problem probably has more to do with your pregancies and (maybe the last vaginal delivery). Breastfeeding and lactation should not have an influence on your bladder continence. Your weight and any possbile delivery related tissue tearing or stretching are more likely causes. A urogynecologist should help you sort this out.