14 year old sheltie with concurrent kidney disease and multiple heart issues euthansia question

Hi - My dogs name is Misha and he is just over 14 years old. He was recently diagnosed with degenerative mitral valve and tricuspid valve disease, pulmonary hypertension and suspected congestive heart failure (MMVD stage D )- who was placed on multiple cardiac meds and this past wednesday started vomitting and not wanting to eat so I took him to vet and they said it was his kidneys. He was dehydrated and his kidneys were failing - likely caused by the heart meds in part (althought he did have chronic kidney failiure prior to taking these meds) so essentially going into acute kidney failure - there wasn't alot they could do because they can't give him fluids or his heart will fail - so they told me to give him some meds for three days to stop the vomitting and increase his appetite and see if he could start eating. They also took him off most of his heart meds except for the ones he can't live without. They want me to check his blood work in a week. So I took him home and did what they said - this is now day four and he does look better - he is eating but not his regular food and not as much as he should eat - he has no problem drinking and drinks like a fiend of course and pees and pees. The theory is that if he drinks and eats and they remove the source of the toxins (ie the medications) that he will get better because his kidneys will start filtering better.

As the backdrop to this, he had been doing well prior to this incident - his cardiac meds worked well and didn't appear to cause him any outward difficulties until this.

I have him seen him slowly look better each day - but the first two days were very difficult with trying to find anything he would actually eat. He is still very challenged that way at present.

I had arranged to have him euthanized today - but he looked so much better I cancelled it. I realize that what is making this so difficult is that I am not ready to say goodbye and feel like I never will be. But he is a very sick dog realistically - I have an appointment tomorrow for in home euthanasia. Am I doing the right thing? Should I give him more time to clear? Feeling lost a bit and unsure if I am selling my dog short. Any thoughts?
Thanks