I second Sharrow on Rachels Vineyard, they are pro-life and have a religious ethos which doesn't suit everyone, saying that I know one girl who has gone and found it really helpful but its seems to be all about asking for forgiveness which is not something I agree with at all.
I had an abortion myself a few years ago, the first year leading up to what would have been the due date is hard, it is like a watershed when you get past it though so hold on to that.
I don't have experience of knowing someone who had a baby at the same time but I did get pregnant again 4 months after my abortion. I have a 2 yr old son now and I was worried sick I would always see in him the child I didn't keep but it hasn't happened.
If you are in the Dublin area I am involved in a post abortion support group that meets once a month. We are non agenda and come from all walks of life. If that isn't suitable there is an amazing website called passboards.org - its an after abortion support board and has an online counselling service which is excellent.
You will always have this in your life and while you might feel you will never get past it you will, I look at myself in the months after my abortion and look at the person I am now and I feel really proud of the progress I have made. Its made me a stronger person. It didn't destroy me, in fact its been the making of me in some ways. Just remember you will too come out the other side xx