Beyond stressed

I seemed to have found a new thing to stress me out. Trust me, it's not by choice. It's my cat, Jasmine. I adopted Jasmine 4 years ago from a rescue cat shelter. She was 9 years old, a beautiful Ragdoll with the prettiest blue eyes. Her original name was "Boobies" (I don't make this shit up) but I quickly changed that, even when the adoption coordinator suggested I just call her Boo for short. Jasmine was my cat. She lived with me in my tiny 500 square foot apartment for a year before Brandon and I saved up enough money for me to move across the US to be with him. But somehow after he and I moved in together, she became "his" cat. I think it's because he has such a long lap (he's 6'3") and because he gives off so much body heat, he's like her personal heating pad. But Brandon deploys a lot. He is now gone on his third deployment. Each time he leaves she gets stressed out. She starts puking on the floor and marking my clothes with her pee. I have to shut her out of our bedroom so she won't climb up in the laundry basket and piss on my stuff. Now that we have a two-bedroom house we put her litter box in the second bedroom. She sleeps on the futon in there and get her hair all over it. I don't bother cleaning it off, she'll just get it hairy again a week later. So we threw a crappy blanket over the sheets and let her lay all over it. Today I was sifting through the spare room for some stuff to donate to a rummage sale. It smelled funny in the room but I knew it wasn't the litter box. I walked over to the bed and pull back the comforter. She had been crawling underneath the comforter and peeing on the sheets!! The thick blanket had masked the smell but when I uncovered it the stench filled the whole room. I was beyond pissed (pardon the pun). I had to throw out the crappy blanket and now I'm washing the comforter and sheets. I'll probably need to do it twice. I'll also need to steam clean the Futon to get the smell out. I'm at my wits end. If I lock her out of that room she'll just find another place to pee, probably downstairs on our nice couch. I don't want to get rid of her, I've never given up on a pet and gotten rid of them because they inconvenience me. But we're trying to start and family and if we're successful it's only going to get worse, not better. She's only going to have to deal with more chaos and noise. She's 13 years old. I'm not sure if she's just old or if she's stressed. Her teeth are bad, she can't really chew her dry food anymore. She leaves crumbs everywhere because she can't chew it all so now I have to supplement with wet cat food. I got an estimate to fix her teeth 2 years ago and the doctor told me $600. For an 11 year old cat! Forget it. I love animals but I am not going to spend thousands of dollars on surgery and tests just to prolong their life by a year or two. It doesn't make sense. Am I being cruel? Am I overreacting from a little pee? Perhaps I should clean her litter box more, or crate her while I'm at work, I don't know. I wish Brandon were here so we could discuss it. But for now, I'll have to figure things out on my own. This sucks