“I have been through worse” is the worst line you could ever say to someone who vents out their pain to you. No pain is better or no pain is worse. They all are equally painful. And just because they have already suffered pain does not mean it will hurt less when they suffer the same again.
For a 11 month child pain is when he stumbles while walking or hits his head while crawling. For a 5 year old kid pain is loosing his favorite toy. For a 10 year old pain is falling from a bicycle or getting scolded by his favorite teacher. For a 15 year old teenager pain is loosing a friend due to misunderstandings. You know that they will face worse when they grow up but you don’t reprimand them for crying over what they consider as pain. Then why do you tell your friend that their pain is nothing just because you feel you have been through worse.
Also many a times you don’t understand someone’s pain because you haven’t been through those situations and even if you have circumstances weren’t same. And that is perfectly fine. You cannot always understand the pain so you cannot always empathize with them. But just because you don’t understand someone’s pain don’t undermine their pain. Even if their pain feels like nothing to you. You sit there and listen to them. You don’t even need to advice unless asked because they have already heard plenty of that. You might have been dealing with pain all alone throughout your life but not everyone can. Having a person to confide pain makes it feel much lighter inside someone’s head. If you can’t help them feeling better don’t make it worse for them.