First thing first, know that motivation is just momentary, you are not going to be always motivated specially if you don't have any exam scheduled. What works is discipline, the discipline you have will determine the end result. Trust me, I also struggle a lot with discipline because honestly keeping your instagram closed and taking online lectures from the same mobile phone is difficult. Like who wants to work when you can recline on your chair and just chill on social media. But the discipline that you still close your phone start studying will do wonders.