Did I kill my cat?

[queensonia]

Back in January I adopted a 3 year old cat. In April, I took her to the vet with a slight cough and found out she had a form of heart failure. The vet advised me to euthanise her because the prognosis wasn't good and I quote "she would die a horrible death". As she was still well and enjoying a normal life, I opted to put her on medication instead.
I really didn't want to be the one to end her life.
She took the tablets with no problem. But fluid started to collect in her lungs and stomach making her breathing laboured. When it began to affect her, I had the fluid drained from her chest and she was fine again for a month and then I had to have it done again. She didn't have insurance and the second time was at an emergency vet but I wasn't going to end her life just because I couldn't afford it. When I brought her home from the vet's the second time, she was so happy to be alive and even more affectionate than usual and was purring non stop as if she was grateful for what I had done. I decided that if she needed to have the fluid drained every month I would happily pay for it to keep her alive. A week after she came home, she was still fine, eating, drinking and cuddling as normal. On Friday afternoon I went to give her one of her tablets - it's a very thin tablet and she has half at a time which I normally break it into quarters. For some reason, I gave her the half tablet in one piece. She more or less immediately started gasping for breath and died about five minutes later. Now I am traumatised by watching her die in such a horrible and painful way and also guilt stricken that the tablet may have somehow choked her or got stuck in her airway. I tried turning her upside down, blowing into her mouth, stroking her neck, putting water in her mouth but nothing worked.

If this was the natural result of her illness I can sort of deal with it, but if I killed her by giving her a tablet, I honestly don't think I can live with myself.
Does anybody know if a tablet would dissolve before it could kill her?
The drug is Libeo and it's a diuretic. If you have read this far thank you.

The number of us who’ve pilled a reluctant cat, they’d be dropping like flies if it was a good way of choking them.

Im sorry you lost her though. It’s never nice however it happens.

You didn't kill your cat, you gave her the best possible life she could have in the circumstances. I imagine the vet knew what her death would be like for you and was probably trying to avoid that for you.

A cat of mine died, gasping, for breath, just as a gave her a tablet. She was 19. I too thought I'd killed her. The vet told me that cats don't have the same sort of airway set up that we do (which we have in order to be able to talk) and it's much more difficult for a cat to choke than a human. And therefore the most likely cause of death was a heart attack, which presents in the same way.

@thecatneuterer I didn't know that! Thank you for sharing that information - it really helps to know that. Sorry about your cat. 19 is a terrific age - you must have been a fantastic mum.