Not feeling well

I have 2 cats 5 year old brothers. One of my cats has been eating fine but losing plenty of weight the past few months. I brought him to the vet last summer( he always freaks out) they gave him trazadone and he stopped breathing. The vet was able to revive him. The vet could not do a EKG but told me that he has liquid in his lungs and possible heart condition. I had major surgery last week when I arrived home he was not himself. He seemed tired and was hiding. I thought maybe he was upset seeing me in post surgery condition. However, a few days have gone by and he’s not doing well. He’s hiding and looks weak. He’s been whining to me. I feel so bad. I cried so hard today. His breathing is 37 per minute. He doesn’t seem to be having breathing issues; however, he’s obviously distressed and miserable. Every night he waits for me by the bed and is exited to cuddle with me. We have such a bond. I love him so much. It’s so difficult to see him like this. Last night he made an attempt to come into bed with me. After a few mins he made his way to the floor and just leaned up against the wall. The vet his coming to my home tomorrow. I am so upset and my heart aches for him