Please take some time to go through the site, post on the message board there.
You can also look for a pregnancy center near you - many of them offer Post abortion counseling. It's really important that you find a way to heal from this. Please don't be afraid to call them or go for help.
It sounds like you were coerced bigtime. Your friends all painted a dark picture of how things would be, and they were dead wrong! So you made a huge mistake, and now you're paying for it. Your friends aren't, you are.
First of all, don't take the blame for what they did to you. You let them make you afraid, and you went ahead with it. And you obviously do need healing.
None of us deserve not to have something bad happen to us. Each of us has her own things to deal with.
Here's a place where you can find a crisis pregnancy agency. They have counseling and programs for women with your experience, and most of the people involved have been through what you are going through.
Afterabortion.com has some excellent discussion groups. They can take you to a particular point. To experience total healing, you will need to seek God's forgiveness and be reassured He has freely given it. That's what some of these programs can do for you.
Good luck with this. Come back any time you need to talk.