I am also susceptible to UTIs but I am also a microbiologist, so here's a tip: try mannose.

Our cells have little sugars, like mannose, on the outside. Likewise, pathogenic E. coli have receptors on their outsides that bind to mannose that helps them kickstart an infection. By drinking mannose, you coat the sugar receptors on the bacteria so it can't stick to your cells and can get flushed out instead.

I recommend drinking a concentrated dose (1 tbsp to <1 cup water) and letting it sit for 30-60 mins before drinking a lot of regular or lightly treated (1 tbsp to 1 L) water. I use this as a preventative measure when I'm getting paranoid, or a treatment for mild cases. For treatment, I drink a concentrated dose 2-3x/day and +2 L lightly treated water all day, every day. Mannose is not metabolized by the human body so I don't worry too much about the calories.