In desperate need of advice. (Long post)

I am 17 years old. I graduated high school when I was 16, have had a job since as soon as I was legally able to, and I have been raised in a Christian (not crazy bible thumpers) household my entire life. My parents married at the ages of 19 and 21 and waited 5 years to have kids. I have a 20 year old sister and a little brother. I love my life. I have been in a relationship for over a year and I love him. This is not immature puppy love (I have been there), this is the real thing. I know I have an amazing life ahead of me, but I have always wanted a family and I love kids and have tons of experience with them. One more fact about me...I am 5 weeks pregnant. The father of this baby does not want it. He has had his life planned out since as far back as he remembered. His mother had him at 18 and she wants me to get an abortion (although the woman has always hated me for "stealing" her son). His step father wants me to get an abortion. My parents have told me that they will support me through anything that I decide and so have numerous other people, but I don't know what to do. I am a people pleaser and feel like maybe I should just have an abortion and make everyone happy. But at the same time, the thought of harming this sweet, innocent little baby kills me inside. Adoption is not a realistic option for me because it would tear me up. It would be unbearable. I feel like I'm at a dead end because my life as I know it will be over if I keep this baby but I just can't get rid of it. I care about it, I love it. Somebody please give me any kind of advice. I feel like my life is falling apart. Please tell me that there is a good life to be lived after keeping a baby in a situation like this...