In no way are you a "monster" for wanting to keep a healthy flock. I think the worst thing about being new at keeping chickens and purchasing sick chickens, is learning that many chicken diseases can sometimes be treated but never cured. The chickens remain carriers for life and can infect other chickens.
I agree with
@MysteryChicken, that based on their symptoms you report, the roosters probably have MG. (Mycoplasma gallisepticum) I also agree with others that it is good to cull the sick roosters and send one to your state lab for necropsy. The main reason to do so is the roosters may be silent carriers of other infectious diseases too.
MG is treatable with tiamulin (Denagard), but not curable. If you want to only keep symptom-free birds, then cull any birds that become sick and breed only the symptom-free birds. (Keeping in mind that all your birds both present and future are likely silent carriers if your current chickens have been exposed to your sick roosters.) If you desire a completely disease-free flock, your best approach would be to start completely over and purchase day-old chicks from a reputable hatchery. I am an animal lover too and chose to treat my first flock that carried MG, but you are not a "monster" if you choose a different path.
Im sorry you have experienced this. It happened to me when I first got chickens too. It's no fun at all dealing with diseases that can't be cured.