A few years back I was also investigated for a sore throat, trouble swallowing, lump in my throat. I think I was in peri at that stage but didn't realise it - I had anxiety over numerous things. There was nothing wrong with me. The consultant did say that as we get older, all our muscles slacken including our throat muscles. (Though I think that was partly due to kindness, maybe she sensed it was just health anxiety.)
I should imagine it's just anxiety. I've just stressed myself out over a different health issue. Hope you feel better soon and try to find ways to relax / de-stress. I intend to get more exercise and generally stop neglecting this old body of mine. And I'm going to get back to meditation, even if it's only a few minutes in the morning.