2 Year Old Kitty with heart murmur

I have a 2 year old male neutered cat with a diagnosed level 2/3 heart murmur. When he was diagnosed they took X-rays and he has an enlarged heart with scarring in his lungs from it. The vet described it as asthma from his heart pushing on his lungs/breathing tubes. I passed on an echo and medication because he was acting like a normal kitten and absolutely hated the vet and had to be sedated for his X-rays. I wanted to save him the stress that the sedation would cause his organs.

A couple days ago he started throwing up in the morning (at least 6 times, a couple were a hair ball, and a couple were grass because he escaped while I took the trash out). He seemed fine and was eating and being a jerk and stealing stuff while hunting me and being adorable. I'm working long hours at work at a power plant so I haven't been able to watch him as much as I would like, unfortunately. I got home last night and he was napping next to me while I was reading and I noticed that his breathing was really shallow so I counted his breaths. His breaths per minute was 40ish, compared to 20ish when he was diagnosed and I caught him napping.

I'm terrified for him. I have someone dropping him off while I'm at work because I can't get out of it. They're going to check him out when they have time and let me know. I'll try to figure out how to put a link in of his breathing video and lung x-ray. Im preparing for the worst but really hoping this is just something medication can help with.