Hiya, For Months Now I Have Had Phlegm Stuck Between

Hiya, for months now I have had phlegm stuck between my nose and throat, I do not have a cold or runny nose or a cough. Obviously when I lie down it seems to get worse and is causing me to snore at night (which you can imagine is great for my partner) I drink lots of water each day as that's all I really drink and I have tried tablets that are meant to get rid of phlegm. But I don't know what to do anymore, do you have any suggestions?