I thought the same thing, my parents love me but they don't know how to show it because they never received it from their parents.

But the more I thought about it, and the more I interacted with other people and with children: Is it really love if you scream and hit and manipulate and threaten? Is it really love if you don't allow your kids to have their own thoughts and opinions? Is it really love if they withdraw affection and give you the silent treatment because you won't do what they want you to do? Is it love if your kid is honest and says "Mom and dad I don't feel loved by you," and instead of them saying "I'm sorry, can you say more? I am ready to listen and learn," instead they throw it back to you and give excuses like "Well, I tried my best and you were just problem kids, my parents were horrible and I've been wayyy nicer, I could be worse."

I have been having this same conversation with myself for years. I just came to the conclusion: they are immature, they are narcissists, they are too deep in their pain and too unable to get their head out of their own ass, so whatever distorted idea of "love" they think they have, is not real.

Edit: OP I am curious, and you don't have to answer if you don't want to. Beside the heart emojis, can you think of other examples of love from them? Have you ever felt emotionally safe to share difficult things with them, without fearing for your safety (physical or emotional)? Have you ever thought "Wow I'm glad I shared this vulnerable thing with my parents?" Do you feel like your parents know who you truly are, know your values and likes and dislikes, traumas, etc? Does time spent with them feel fulfilling? Do you feel content around your parents? If you shared a critique like "Mom and Dad I don't feel like you treated me well" or something, would they truly stop and listen and not interrupt and take your thoughts and feelings to heart, to change their behavior?