I can relate in a way. My mother never contemplated abortion, but my father was pretty intent on getting rid of me after he realized I wasn't the ideal son, which he eventually succeeded in doing by having me committed to a psych ward. However, unlike your situation, I hated my father and adored every minute of disappointing him and tarnishing his reputation.

I think you need to either confront this and end it, or let it go. Brooding about your mother's mistakes isn't going to change the past. And this is too much to worry about with everything else in your life. I agree with the other posters that you need to find someone to talk to while you sort this out.