I don't think I have had any particularly traumatic event in my life but I find myself having vivid imagination of having one just to make myself more miserable, does this count as self harm?

Sounds like you are having trouble feeling like your emotions are valid. It's okay to feel like this, and you are not alone... Seeking emotional validation is common and can feel overwhelming. In the words of Ryan Weiss, trauma is any moment where our feelings were dismissed. Therefore, according to him, everyone has dealt with trauma. It sounds like you are feeling frustrated with yourself and with your vivid imagination. I understand this, and it is okay to feel this way. It's okay to not understand why you're feeling miserable. Please feel free to chat with me anytime you feel like it!