Why does my throat feel tight and swollen?

[Sheisun]

For the past week or so my throat would feel tight, as if there's something squeezing it. This would only happen occasionally at night, but now it happens every night and continues onto the day. It prevents me from sleeping and is very frustrating, I can't concentrate on anything because of it. I keep thinking it will tighten so much that I won't be able to breathe. I'm also having slight difficulty swallowing. Its very uncomfortable and I hope something can be done about it.
When I looked this up, every website said its most likely anxiety, but I'm prettty sure I don't have that. Is there anything else that could be causing this?