The Prophet (salAllahu alayhi wa salam) informed us in various narrations that the eye that sheds a tear for Allah will never be touched by the fire and its owner will be in the shade of Allah on the day of judgment.
Abu Bakr As-Sideeq (may Allah be pleased with him) was well known for many things. Amongst them was his frequent crying. Every time he prayed he cried, and in fact it was difficult for people praying behind him to hear his recitation because he was always crying.
Despite that, once during his rule a group of non-Muslim men came from Yemen and asked to hear the recitation of the Quran. As the recitation began, the men immediately broke down into tears and Abu Bakr cried at their crying and said “this is how we used to be before our hearts became hard.”
What was Abu Bakr talking about? He was still known for his tears until the day of his death! But its only natural that as time goes on, the emotions you have towards faith start to fade.
Imagine the first time you took shahada, the first time the Quran really impacted you, the first time you really sincerely repented, the first time you lost someone you loved, the first time you ALMOST experienced death, etc.
Now what if you’re trying to cry but finding yourself unable to, Abu Bakr (ra) said then make your face as if you’re crying until you actually start to cry. In other words, fake it till you make it. Not in front of people as a form of showing off, but in solitude.
Find that verse that really gets to you, try to feed off of the emotion of the Imam or the people around you in taraweeh, think deeply about paradise and hellfire, make a dua from the bottom of your heart, and force just ONE tear out of your eyes. And that one tear might be the one accepted deed on the day of judgment that saves you.
Oh and one more VERY important thing, DONT TELL ANYONE ABOUT THAT TEAR so that it can remain solely for the sake of Allah.