if you don't think you could go through with an abortion then don't - explain to your bf why you feel that way and hopefully he'll respect that (I am pro-choice btw but you should be sure of that decision). give yourself some time to get used to the idea of being pregnant and keep talking to your partner.
Do you have any other support around you?
You can manage, it may seem impossible atm but, depending on where you live you should be entitled to some help financially, look into any financial assistance you could get and hopefully that should help aleviate some concern.
good luck
oh yes and adoption is an option as Jules mentioned