I Have Many Fears

I have a a big fear that no one loves or likes me. I know that probably sounds petty, like "of course people love you,bla bla bla." But,I seriously have a hard time believing that someone loves me. Even as a kid, I didn't think people loved me or cared anything for me. I still don't think my mom or dad does. In relationships I will constantly ask my partner if they love me or I will tell them I love them and miss them all the time because I don't want them to think the way I do. I know to some people that's very annoying, it's not a lovey thing for me, it's reassurance because I have a hard time believing even with my siblings. I don't tell them I think this way, I just honestly wonder and have a hard time thinking it. So really I'm just wondering if anyone feels the same? Have you gone all your life thinking you don't matter to anyone? That if someone confessed their love to you that you wouldn't believe them? That your parents or siblings or anyone of any importance to you never and will never care about you? I don't know why I think like this. I know people and I know without a shadow of a doubt that I care and love them, but I always fear I mean nothing to them. So, I try to constantly be there for them and tell them I love them so that one day I will think that they actually love me back.