Sasha I still have night accidents, nothing odd about wearing one for that
Definitely nothing to be ashamed of, but absolutely something to be concerned about. I work in pelvic health (not a doctor, not giving medical advice) and if a 22yr old with severe incontinence showed up to our clinic she would definitely be going for further tests.
Is this something you've investigated further? When was the last time you had a pap smear / bloods done? Have you always had this issue or is it only since your pregnancy scare? Have you been screened for cervical cancer / bladder cancer / tumours / growths / polyps?STDs? Infections? Kidney stones? Neurological disorders? MS? Parkinsons?
There are so many potential risks here, some are easily treated while others are life threatening. Investigate further. Wearing a diaper at night doesn't solve anything.