Voice issues

Hi my son who is 20 has had a problem with his voice for the last 3 years . It's not a stammer or a stutter , it's like his voice goes dry and the words don't come .( like someone has grabbed him by the throat and stopped the words coming) . He used to have bad tonsillitis so he got a tonsillectomy and adenoidectony and he also had a deviated Septrim corrected which we hoped would correct this but it has not .

I am a nurse so have managed to push for investigations he has been to speech therapy and had video voice investigations but it shows there is nothing with his voice box . He is very tall and this happened within about a year he seemed to go from 5"7 to 6 "1. At one point he struggled to sit on his knees as his muscles were so sore ( GP thought it was just his bone had grown faster than muscles) this appears to be alright now . He started working as a mechanic and he states he does have really bad reflux , he takes galviscon and I have raised his bed slightly , he also has bad breath . We have a history in the family of an essential tremour and I did wonder if instead if the tremour it could affect his voice , but guessing and now grasping at staws as this holds him back , he texts rather than speaks on mobile and does not go out much and he is a really nice handsome lad . I have tried accupuncture as well . I even contacted the mcquire programme regarding stammer school but he won't go . A new young GP that I work with suggested helicobacter . After all that history do you think there could be a connection .

Regards jill morrison