A Kegel is what you described only hold it for about
10 seconds then release. Wait at least 10 seconds and do another one. Do a total of 10 Kegels 3 times a day. This helps build up your pelvic floor muscles. When you had your surgery, the surgeon removed a sphincter muscle near your bladder. That is why you leak.
It took a while before I had my first pee. Sometimes you feel like you have to go then just a dribble.
Just remember, you went through major surgery, your plumbing is going to take 1-2 years to get back to normal. This is the "new normal" for now. Don't fight it, accept it. Things will change over time.
Bill from Florida