Did you have urge incontinence? (Sudden urge or spasm that results in leakage.) That is usually what Botox is used for. Almost sounds like you have more stress incontinence.
I have had Botox three times, and while I have had to cath for a short while afterwards, my bladder eventually starts working again. This is usually within a month or so.
If you are still having to cath after a year, makes me wonder what went wrong. I would see my doctor.
How much do drain out?