I feel like there's still something in my throat and sometimes it's hard to swallow saliva. I don't have any other symptoms. What could it be?

Good morning! I do not know where to ask this question so I hope that here will get an answer. From 3 weeks? I have a feeling as if someone was still in the game and sometimes hard to sline przelyka. I don't have any other symptoms and this feeling always comes up in the evening. What could it be? I'm 18 years old, I asked my mom what it might be like to have something in her throat and she said she also has a similar allergy. I'll add over time how "charknę" to better swallow this saliva is dense and resembles the appearance of phlegm. Cyz is something serious? I read on the internet that it can be esophageal cancer, etc. Please answer because I am very anxious