Pelvic floor weakness

Hello Mr. 37 years old, I had the problem of leaking urine after the bathroom I started Kegel's exercises. First I could clearly contract the pelvic floor muscles for a few seconds and then drop them.I had read on a site that it is useful to contract muscles several times after the operation, when I contract the muscles after the operation, the remaining urine remains and after the restroom no other urine.But now, when I contract the muscles, the contraction does not last long and it ends early and at the end I don't feel the muscles being released at the end of a few seconds..Is this due to the fatigue caused by the exhaustion or is it harmful to the postoperative muscles?By the way, in sexual practice, the penis is not completely firm. Is it due to the weakness of these muscles?