How would you feel?

Soooo my mother and father went through a time were my mother wasn't very faithful and she got pregnant! they had my dad tested and it showed that he was no longer able to have kids. they knew the baby wasn't my dads at this point! My mom wanted to have an abortion but my father didn't. he always wanted more than one baby and he just found out he can't so at this point what's done is done (he is against abortions). he wanted her to keep the baby and raise it like it was one of his own. she didn't want that and so she had the abortion anyways! dad was sad but went on with life! they hide it from me I didn't find out until I was 19. Well a few years down the road my relationship with my mother is worse than it has ever been! She tries to guilt trip me into everything and I can't help but feel like maybe she wishes I was the baby she gave up because maybe that child would help her and love her! on the same note I am also upset they gave up my only chance at having a brother or a sister it kinda breaks my heart!! I have never told or asked them about anything to deal with this. i was informed by other family members and I just don't know if I'm a bad person for thinking that or if I shouldn't be thinking that. I know what I feel I just don't know if that's right or if i should talk more to my dad about it! I don't want to hurt him again! I feel lost and confused and very conflicted!!