Not ready..

I am 19 years old and 5 weeks pregnant.... I am not ready for this, I don’t want a baby right now. Yes I am the one who laid down and let it happen, I take full responsibility for it and I would NEVER end the pregnancy early. I just have a lot of time to think because I’m always alone. I have so much I want to do in life and I can’t with a baby. I always thought that I’d be excited if I ever did get pregnant but now that it has happened.... I want to take it back.... I can’t talk to my SO about this because he will just get upset but I’m terrified and regretting this whole relationship now.. I don’t want to think like this... I have no idea what to do.