Well, every day since that abortion you have felt angry, very sad and yes, you probably have had some degree of depression. I am concerned that your anger and disappointment at others (and yourself) will allow you to make a decision to "make up" for what you consider to be a huge mistake. Having a baby now, at your age and level of depression, confusion, and hurt, would not be a healthy decision for you or any life you would carry. Marriage and having children should ideally be entered into when you are feeling strong, joyful, and confident at all levels. You're not in that place now, Christy. Having a baby now won't make your pain go away about the abortion, it's the wrong way to approach your depression and angry feelings.
Please research a good therapist you could see to begin dealing with these long-held emotions. You deserve better feelings than you are capable of feeling now and I guarantee you it's possible to feel better, more alive, and free from chronic depression. It will take work but I know you are up to it. For some good advice on therapists who would really understand this special issue, I'd suggest calling your local or regional Planned Parenthood office listed in the phonebook. They are a compassionate organization who will understand immediately what you are talking about and they will have some good referrals for you. Keep me posted if you think I can help further.