Is it necessary...?

I recently got my first UTI, possibly from having sex and not going to the toilet afterwards. In a matter of days, the bacteria travelled from my urinary tract to my bladder, from my bladder to my kidneys and then ended up in my blood causing potentially life threatening infections (pyelonephritis & septicaemia) that had me in hospital and home care for 12 days and I am horribly afraid that it will happen again...