Something is wrong with Scout

I'm concerned about Scout. He is coughing and wretching about 30 times a day. He doesn't throw up any food but sometimes he coughs up phlegm but it is clear. He sounds like he has some congestion in his lungs, but I don't know. I called the vet this morning and they said they definitely need to see him. In terms of energy nothing is changed he is still very energetic and excited to be around us or visitors. I hope he is ok. I'm kind of freaked out because I don't want him to suffer the same kind of demise that Rocky did. I've really been traumatized by Rocky's death and it makes me want to be very careful and make sure I get him to the vet if there is anything remotely wrong with him. I go at 10:00am this morning. Hopefully it won't be anything serious.