Hi, transient loss of voice and hoarse voice are the typical symptoms of laryngitis. It is inflammation of the larynx (voice box). It is mainly caused by virus and treatment depends on type of virus affected. Even serological tests will help to identify the responsible pathogens. It can be treated with appropriate anti viral.
But drinking lot of fluids, sucking lozenges, gargle with salt water, breathing moist air to soothe sore throat, refraining from taking decongestants (because they dry your throat), resting your larynx will help you. Antibiotics and anti inflammatory against prescription will help you. I suggest you to consult ENT specialist. Take care and regards.
This sounds like possible acid reflux issues. I lost my voice last year and it was reflux. Talk to your doctors about trying reflux medicine to see if it helps. Asthma can cause a very temporary loss of voice with an attack but not a prolonged case of laryngitis.
Take care a feel better.