End of a marriage, an affair and now an abortion

I have been unhappy in my marriage for about 9 or 10 months now. We have a 2yr old daughter (our rainbow baby) which makes this very complicated. I found myself a couple months ago, attracted physically and emotionally to someone else. We ended up sleeping together and relied on the pull out method. Well we screwed up and I ended up pregnant.

I found out about being pregnant just my husband found out about me not being in love with him any more and I had told him I want out of out marriage. I told him I wasnt pregnant (bc at the time I didnt know). I have scheduled an appointment at planned parenthood on Tuesday to schedule an abortion bc neither I nor the father feel that this is the right time nor environment to bring a new life into this world. I'm terrified and emotionally, not sure how I can handle this after losing a child of my own already.