Hello,
It can be due to post nasal drip and sinusitis. Get an evaluation done from an ENT physician and get transillumination test and CT scan of the sinuses done. Till then inhale plenty of steam.
I hope it helps. Take care and regards.
The mundane explanation is:
drainage: allergic rhinitis or other sinus issue
throat tightness during stress: normal reaction for some people to emotional/stressful situations. When i am very upset, I literally cannot speak...my throat is too tight.