Hello and welcome. My name is ***** ***** I'm a biologist with a special interest in reptiles. I'm sorry to hear your dragon is having a problem.
I wish I could give you a home remedy to try, but this is a situation where it's better to be safe than sorry. With the symptoms of not eating and making vomiting noises, your dragon may have something caught in his throat, he may have a respiratory infection, he may have something wrong in his digestive system. There is no way to know without a vet exam. So, yes, the best thing to do would be to see a vet. This link will take you to a directory of reptile vets:
If you can't find a vet there, let me know and I'll try to locate one for you. If you have more questions, let me know in a REPLY. I hope your dragon will be fine.
My goal is to provide you with excellent service – if you feel you have gotten anything less, please reply back, I am happy to address follow-up questions. Please remember to rate my service only after you have all the information you need. Thank you!