This quote means that the person it's talking about is missing someone a lot. The first part, "You're Everywhere," suggests that the person they're missing is always on their mind. Even though they might not be physically present, their thoughts and memories are all around them, like in the places they used to go together or in their heart.
The second part, "Except Right Here," points out that the one they miss is not with them at that moment. It's like there's a space or an emptiness where that person should be. This absence is what causes the pain.
The last part, "And It Hurts," simply tells us that this situation is causing the person a lot of emotional pain. So, in a nutshell, this quote is expressing the feeling of missing someone so much that it hurts because they are not there with you, even though their presence is felt in other ways.