How do i stop peeing when i cough?

Many factors: This is called stress incontinence. Many factors including age and prior surgeries. Usually difficult to find one definitive solution. Obviously, treat illness that is causing chronic coughing. Reduction in weight (if overweight). Reduce consumption of caffeine or alcohol. Talk to gyn dr about pelvic floor exercises. Plan frequent toilet trips. Google "stress incontinence" for more options.