I was pregnant at 21. My twat of a boyfriend left me when he found out. My options were to either move home, marry him and stay at home and look after the children and himself, like a women should or abort. He was such a charmer it was rather hard resist his offer of domestic slavery .
I chose to go it alone. It was hard. I was scared. There were many days when I was certain I had made the wrong choice and felt like kicking myself for not aborting.
After she was born I just sort of muddled along for the first year. Feeling a bit numb about it all. Looking back it was pretty clear that I had PND. Not surprising considering that my life had turned upside down within a year I had lost my boyfriend, my home, my job, my friends, had to move away from a city I loved to be closer to family and had another little person who depended on me for everything and thanked me for my efforts by crying constantly.
Dd1 is 6 now and my best friend at times. A little sod at other times, but I wouldn't change her for the world. It was hard worth, but she was worth it. Her 'father' has nothing to do with her. He has never even seen a picture of her. I feel bad for his parents sometimes as they have this wonderful granddaughter they don't even know about. But at the end of the day, he is the one missing out.
I'd make the same choice, given my time again. As another poster mentioned, when my children are older I will still be young enough to enjoy my life. And I will be young enough to enjoy them growing up. Even the clubbing years
It's not easy. No one can tell you it is. But it's do-able and probably not as bad as you are expecting it to be.
I'd suggest you get referred for counselling to discuss your options in rl, with someone who is qualified to give you advise. I think Marie Stopes offer this service if there is one close to you. They are not there to judge you and have heard it all before, so no panicking.