you are right about some things, but you are not being a horrible person.
she was/is using you.
first fact, is that a child is blameless, and her not wanting to see you, back then seems selfish on her part, and very terrible of a parent, rejecting bond with your child.
if you know the philosophical term, "tiger to gazelle transformation", you'll know, that she's doing this, because she needs you right now, to make her life comfortable, at your expense, as a child, they can throw you around as they more or less please, because you are utterly dependant on them, the tiger phase, when you grow up and near the state of independence, they slowly change to gazelles, it's understanding how power goes into play often, when you can't strong arm yourself around something, try make yourself look like a frail victim, grants pity and help/support, it works, and it's insane.
The part of you feeling yourself as a terrible person, is the so called, "inner parent", where, what you think, what your parents think/expect, more or less tells you what to do, this is common from an authoritarian upbringing, and such a feeling will always surface in any family gathering, you'll understand it, as you change yourself into something you normally don't do, unless you don't care.
the fact she ignored you, when you needed her the most, a child being abandoned by it's parents, when in peril, is terrible.
You really don't owe her anything.
