DESPERATE...PLEASE HELP.

i REALLY need some advice. i have had a cat for twelve years that i have raised from a kitten. i have spent a great deal of money over the years keeping this cat healthy and alive and i love her like a family member. in the last year and a half i have adopted another cat who is very friendly with both other animals and people. my old cat HATES this new addition to our family. i tried everything that was recommended to me to get the older cat to accept this new kitty, to no avail. since this new adoption the older cat has displayed some behavioral problems: hissing (at people and the other animal), fighting, and most notably, chronic urination and defecation outside the litter boxes (there are four, i was told two per cat). i have spent hundreds and hundreds of dollars on cleaners, vet bills (she was treated for a bladder infection but the accidents have not stopped)...i have tried everything to get this cat to stop, to no avail. friends have recommended just getting rid of the cat since she is old and displaying behavioral problems, but even the thought of that makes me feel horribly guilty. i know of no one else who would want to take the cat in, nor do i want to give away the other cat as i love him dearly also. i have no idea what the right thing to do is and i absolutely cannot afford to keep spending money on costly cleaners and vet bills. PLEASE help. i am desperate and at wit's end.

DO NOT PANIC (in large, friendly letters)
   
ODO NOT PANIC (in large, friendly letters). There's usually a solution to this kind of problem.
   
Okay, we know this: Your cat's not going to thaw to Junior if it's been 18 months & she's still really, really angry. Her bad mood's spilling over into the human area.
   
QUESTION; Is the younger cat insisting on trying to play with Senior Citizen? This is important because if the kid's trying to play, & the old cat doesn't want to, this is likely the source of the old cat's continual bad mood.
   
Conditionally, I will say this: This is a classic situation. I've gone thru it twice already. In my cases, the pairing of 2 young cats did wonders for making the old cat happier, as they left her alone most of the time after that.
   
Since your youngster's a lively, friendly little thing, you should seriously consider getting another young cat to keep Junior busy (after all, at this point, SeniorCat can't get any more badly behaved). If Junior has somebody his own age to play with, he will likely abandon bothering the Old One, since another kid will be willing to chase around the house with him. He wants a playmate - well, get him one! & (I speak from experience) three cats aren't really more trouble than 2 cats, especially if the addition of the 3d cat calms the inter-cat relations.
   
Should you decide to do this, I recommend: Get a 7 to 12 month old cat. Either a male or female will work. Two males will cheerfully beat up on each other, & a male & female pairing works very well (experience here, again). When you pick out the cat, choose one with the same level of energy & moxie that Junior has. If Junior's a fearless, combative, lively, always-ready-for-a-romp cat, pick the cat that matches that level. You don't want a shy retiring new cat, you need one that will face Junior down on his own turf.
   
In the meantime: Your old cat's just being spiteful. She's angry, mad, pissed off, & wants you to know it. She has no real reason to poop all over the place, but cats can be SO nasty & SO stubborn, that we humans have to overwhelm them to get them in line. She could just as easily ignore the youngster & whap him in the face a few times to make him go away, but if the kid's really persistent, then he probably won't accept "NO" for an answer.
   
Since your old cat knows dang well that she's misbehaving, then you have to bring out the big guns. It's time for:
   
AVERSION THERAPY:
   
"Bad things happen to me when I do this forbidden thing." I used it on one of my (past) cats, & broke her of a bad piddling habit in a week flat. It sounds harsh, but it won't hurt.
   
You're going to need to tie up your bathroom for 1-2 hours. You will be punishing your cat by depriving her of food & attention, & isolating her.
   
When she poops & piddles, grab her immediately by the scruff of the neck: this is a "Mother" action, & you are Mother. You don't have to lift her, just immobilize her.
   
Whap her (in a firm manner) on the nose w/yr finger, enough to make him understand. Speak very sternly (even yell, if that makes an impression): "NO! BAD FLUFFY! BAD CAT! DO NOT piddle on the bed/poop on the rug!! I will NOT have you piddling on the bed/pooping on the rug!! BAD CAT!!"
   

   
Pick Cat up, still holding by the scruff of the neck, the other hand supporting her body. No matter how much she swears, don't let her go. March her into the bathroom, plop her on the floor, & order her to "Stay there!" Then turn on the light & close the door. Leave her alone in the room for at least an hour. Ignore all cries & yowls.
   

   
Then let Cat out - just go by & open the door without looking inside. She'll creep out slowly, wondering what she's going to find.
   

   
And ignore her for at least 2 hrs. Do not speak to her, pet her, play with her, anything. Pretend she doesn't exist.
   

   
If it's near mealtime, don't feed her - denial of food always gets a cat's attention. It won't hurt her to miss a meal (every few meals), & it'll make a point, coming right on the heels of the time in the cells (bathroom).
   

   
After 2-3 hrs, you may talk to her again, but don't be overly attentive: be civil. Make her realize you're still mad. By morning (or evening, if the incident happened in the morning), go back to treating her as normal.
   

   
And every time she pulls the same thing, send her to the bathroom cell again, the same way.
   

   
This may make an impression, & convince her that pooping on the floor isn't going to get Junior out, & that all she gets is hours in a little room & no dinner, & the Forbidden Thing isn't fun enough to make up for the nasty treatment she gets afterward.