Hi there,
I'm also a L1 user. I also faced issue you're facing now. It seems a lot of bigger apps is the main reason usually makes the device slow. Often overheat causes it to work slow too. Another issue is the internal memory or ROM (I don't know why call it ROM. As ROM stands for Read Only Memory.) When you load 90-99 percent of the internal memory it should be low. Perhaps considering uninstalling unused apps, clean up big and unused files and also using proper charger and cable might help.
