Welcome to Healing Well. I found the site 2 weeks before my surgery but you will have plenty of other questions in the coming weeks that we can all help you with.
The symptoms you are having are normal after the cath is removed. You tend to leak more standing up and in the afternoon when your body tires.
Most of us used the Depends briefs and a pad inside the briefs. That way you can change out the pads as needed and leave the Depends on unless it gets too wet also. It is a side effect that comes with surgery. Your doctor should have explained that to you. The sphincter muscle by your bladder was removed with your prostate so you need to do the Kegels to strength your other sphincter muscle at your pelvic floor. Don't over do them like I did, it will only slow your progress. Usually 3 sets of 10, 10 second Kegels are what the doctors order. One set in the morning, one set at lunch and one set at about
dinner time.
I am sure many others will be along to welcome you soon.
Good luck and welcome to the other side,as we say here.
Bill from Florida