@raincloud I am suspecting you may be experiencing interstitial cystitis. A verified and clinically proven supplement to help? Is made by NOW Mannose Cranberry supplement. It is verified GMP ..you can buy it many places... some upcharging it quite a bit... but a 90 count bottle is available at Walmart for $18.88 if ordered online (in my area anyways)..an OTC supplement. I highly recommend you do your research to find the best pricing ... it really does help. (used for years in veterinary medicine and found quite efficacious now used for humans too) My DIL has IC and it is very helpful for her. Her urologist also prescribed Amitriptyline - it calms the Central nervous system as well as peripheral nerves to reduce the chronic pain signals from the bladder and it also reduces the smooth muscle spasms and calms overactive nerve transmissions. It IS a prescription drug but perhaps your GP or an Urgent Care Doc could prescribe for you before you leave out... it also helps you sleep at night.
Avoid the triggers of caffeine (coffee /tea) alcohol, carbonate and fizzy drinks (soda/sparkling water) acidic and citrus juices as well. foods to avoid...include citrus, tomato products, spicy foods, pickled foods,artifical sweeteners and chocolates.
Get those started today or ASAP ... you should start to see improvement by the time you leave out for you trip... not back to normal ... but more comfortable and on the way until you can see the urologist.
Saying prayers and sending Healing for the Highest Good for all concerned. Big Hugs.