My Lenovo K8 note is not charging,its showing "Charging Slow"

hii

my lenovo k8 note is not charging properly,it takes more than 14 hrs to charge, sometimes only 1% is charged in an hour,tried changing usb cables,my charger even work better on other mobiles,even today when I bought a 3.4A charger it worked nice for 41%,after that it turned to worst not a single point was charged for next couple of hours,I even tried cleaning my usb port sounds foolish,but had no ideas left to make it work.

Please help if got any other ways to make it ok other than purchasing a new set