acejka, I'm so sorry. We never hit that point, but the choice was taken away when our cat took advantage of an open door and ran away, while DH was alone and cleaning up the huge mess she had made (pee and poop...she seems to have been sick while we were away and the in laws were taking care of her). But we struggled from the very night we had her; that night I had my very first non-exercise-related asthma attack and it was a BIG one (no diagnosis at that point, no inhaler, just took it a breath at a time), she was extremely needy, she peed in odd places at unpredictable times, sometimes she didn't poop "all the way" and would freak out with what was hanging from her bottom, she had allergies and we worked to find the foods she could have...it went on and on and on... I had a friend who hated that we wouldn't put her out for adoption, but she had all those problems, coudl NOT be with other animals (we were her 4th home, as all animals that lived with her would beat up on her, it was very weird), allergies, etc etc etc...no one wanted her... So while we never got to the point where we gave her up, we were getting close, and it's sickening. It's been 3 years since she ran away...I was just crying about her the other night...
(and we did take her to vets...nothing was wrong except she would lick her leg so it became a festering sore, took us a year to get it healed up entirely...but nothing else was wrong that a vet could fix)
1, cat is approx 5 as the OP said.
2, she addressed that in her post.
The lucky thing for you vs the OP (and our cat) is that she will predictably pee on that towel.