Feliway definitely does not work for all cats - but it may help both with her stressing and with the peeing.
Feliway is a synthetic hormone that mimics the "friendly" markers in cats' cheeks. When cats scratch, poop, or pee, they are scent marking - but territory marking. When cats rub their heads and cheeks on something, they're like... "claiming" it.
Cats are all about scent - thus Feliway was actually developed to help with inappropriate peeing problems. That said - there are cats that spray ON the diffusers.

But more often than not it does help - and especially to help reduce stress in the environment.
We use the spray, not the diffuser. It's a little more work in that you have to spray it every 3 days. But I like being able to control where I'm placing the scent.
However - a big part of helping Feliway help as a deterrent to kitty peeing in inappropriate places, is getting rid of all the "pee" scent that is around - if you haven't been using an enzyme cleaner. Shampoos, carpet cleaners, or other regular cleaning products that you would normally use to clean up your kitchen floor or whatever will NOT work.
I really, really, really suggest you purchase the Nok Out. The way you use it is basically saturate the affected area, leave it for 15 minutes or so, and then blot it up and let it air dry. You can't cheat and set a space heater near it or use a hair dryer on it - it has to air dry. In the Winter with the dryness, it should only take a day or two. What we do is then just set aluminum foil over the area - both so we remember not to step there, and to help deter kitty from peeing there again while the Nok Out does its work. If, once it's dry, the spot doesn't smell just a tad like chlorine - then you have to do it again.
But buying a black light and going through your home at night to identify all the spots she's used you may have missed (shows up as an orange splotch) and using a good quality enzyme cleaner (Nature's Miracle never worked for us) should go along way to getting all the scents back in the right places.
...and offering her more litter boxes - different types in different places - may also help a lot. You can remove the ones she doesn't really like, but for a while there, when we were going through the same problem, we had about 12 litterboxes around the house (for at the time five cats). FYI, the "rule of thumb" is to have one more litter box than you have cats.
Also, does she like playing? Play is a great way to help cats de-stress.
Do you have any vertical space for her? Cats live in a very 3D world, and having cat furniture often helps just with their general happiness.
Also, we provide "cat TV" for our kitties. We have bird feeders that use suction cups to stick on the windows, and either window perches for the kitties or - in one instance - the back of the couch is right up against the bottom of the window. This is GREAT entertainment for them!
But I'm glad to hear she's coming around - at least on the loving.
If you're still having a problem with the peeing, I think you should consider confining her to one room for "litter box retraining" while you clean up the rest of the house - but only do this if you can spend a good amount of time in there with her. ...but relieving your frustration is important too. We've been there, and it can turn into a cycle of stress.
