Hi Leanne ,
I think you are suffering from upper respiratory tract
infection.You should go for the investigations like blood counts and x ray chest , are you having fever also ? what is your age ?
You can do saline gargles and steam inhalation , take some antihistaminic like cetrizine 5 mgm twice daily , any safe antibiotic like cefuroxime 250 mgm twice daily for 5 days and cough expectorant as you said mucous is sticky it is more likely an allergic cough
.It will be better if you show it to an ENT specialist
to see any tonsillitis