Struggling to Let Go of Someone Who Meant Little to Me

Am I fault for missing someone who I meant nothing to very little to? I think about her almost everyday, even when I don't want to.. I wonder how she's doing, if she ate, what she's up to, if she's happy.. and it sucks because I know she isn't doing the same and she's busy living her life.. but it's so hard to throw all the memories away. I hold on to them because sometimes they make me feel safe and they remind me that I can love and it's okay to. But at the same time I hate that I do, I hate how much I care.. I hate then when I face reality no one is there. I don't wanna love anymore, but I'm afraid of the person I'll become of I don't. I try to tell myself to never let the actions of others determine my moves.. yet it feels like every time I love I'm played and I'm used, left empty, broken and abused.. and it hate it. "just focus on yourself" they tell me.. show me how to. That's right you can't because you aren't me and I am not you.. and no matter how much you try you can't fit in my shoes.