Why do I feel guilty?

I am 18 years old still a virgin and im with my first bf ever whom ive been fooling around with sexually..he fingered me for the first time today he persisted and finally i let him and i liked it at that moment..we also undressed but did not have sex..i like him but the reason i wont have sex with him is because i want to do it with the one and i dont feel like he is..although im having fun with him should i leave even if i know this isnt the real deal..weve been together 3 months..i feel like im taking things to the next level with him and im losing control? what do i do?