Sorry to hear that. Sleeping at night has been my only relief...it is a "gravity thing" I think: laying flat removes any/all pressure on my bladder, so no leaks.
From the first day/night after my catheter was removed, I was able to sleep through the night, or...actually, after the first month or so, before I started Pelvic Floor Physical Therapy (PFPT), I was getting up in the middle of the night at about 4:30 - 5:00 a.m. to empty my bladder, until post-surgical recovery aided by the PFPT brought that under control.
I was in health care for 40 years and never learned that as we age, our bladders get smaller. That was in fact my first motivation to get a PSA test done after four years (Yep...foolish of me): In September of 2024 at age 69, I suddenly was having to get up anywhere from 2:00 - 5:00 a.m. to urinate. That had never happened to me before. The urgency/necessity awakened me. I was NOT happy...I hate being awakened for any reason. So, I realized it had been four years since my general practitioner had quietly closed down his practice without telling his patients (ya...a real jerk...no notice to us whatsoever). Because I am Diabetic and otherwise have always been very healthy, I suddenly had let four years slip away. The awakening at night to urinate motivated me find a new Internist, and to get a PSA = 6.1 ng/ml. And thus started the rapid sequence to biopsy, PET Scan, DaVinci Robotic-Assisted RP, and an unexpected/unfavorable outcome based on the pathology report vs the biopsy report: 3+4 = 7 Gleason. Per the biopsy report, my urologist was confident that "we caught it early, you'll be alive in 15 or more years", to the surgical pathology report - EPE, surgical margins, cribriform glands, and left seminal vesicle invasion, making me a pT3b with the near "guarantee" that my cancer will return within the next 5 years, especially with my urologist leaving behind some cancerous prostate tissue (part of "surgical margins"). I am one of the unlucky 10-20% where there are "surgical margins." So...
Your nighttime leaks (or floods) will come under your control in due time. Hang in there. Try to get into the practice or habit of what my PFPT therapist has me doing: Urinate every two hours whether you need to (feel it) or not. And drink one cup of water (8 oz) only before or after you urinate. If you are of normal height and weight for a man, per my PFPT I should be drinking about 48 oz of water every day, possibly as little as 40, and as much as 54 oz. Avoid/eliminate caffeine, alcohol, carbonation, and acidic drinks (Orange juice). All of those are bladder irritants that will make your bladder angry and overactive to urinate. Good luck.