hello and welcome to HCM,
First of all let me start by telling you that since you are a singer, your voice is a very precious commodity for you and you need to take care of the same judiciously. Let us see if we can help you in achieving that:
1. Get an endoscopy
of your vocal cords to rule out vocal cord nodule which can cause similar problems and is quite common in singers. Also this will help us in further treatment and follow up.
2. Meet a speech therapist who will analyze your speech and advice you on how to properly modulate your voice without strain
3. Ask the speech therapist about vocal cord hygiene and follow them religiously
4. Start anti reflux treatment with the consultation of the doctor and continue them properly
5. Ask for anti reflux measures and follow them too
remember that that there is no direct and absolute treatment for your problem. The way you take care of your voice determines your course so take care and do not whisper or scream.
get well soon
Dr Sriram Nathan