I told my bf i was ready for sex..but now i'm not so sure?

just tell him your not sure anymore. don't do it unless you are 110% sure you want to. if he loves you then he will wait forever. I know someone who lost her virginity because she "couldn't think of a good enough reason to say no", she was in your exact situation but she just did it and she regrets and hates herself everyday for it. It's a big mistake. Just wait. It will feel right eventually