You can do this. I completely "get" you. Been there.

There's a third option, which may work better with Metamucil, in case you're not doing it already, which is to UP your fiber intake. Your nurse may offer some suggestions.
When I was first cathed I basically ate pre-packed red-leaf salads, with some roasted chicken and topped it with olive oil & some citrus. This, with the Metamucil really, really helped. Legumes, low sodium and no sugar. Sugar in the gut, helps to feed bacteria that causes the UTI's we try to avoid. Apples, veggies and probiotics will get you through until you are regular. Ask your nurse about these things, they may be covered. I'm in Spain, so vitamins are really expensive- the curse of Spanish bravado- "we get it from food," as they stroll into McDonalds. LOL!

We're behind you. You can do this. One day at a time.