Dont know if i can give the advice you are looking for but i too am goin throught he same thing i met my boyfriend when i was 17 i am now 22 and he is 27 we have been living together for about 2 1/2 years. I am so scared that i am ganna be 30-40 years old wishing i would have lived my life to the fullest and not settled so quick. I love him sooo much hes wonderfull but I have this thought in the back of my mind " what if hes not the one" i was so young and have yet to experiance a lot of things and im worried i never will. Its so hard to see myself with out him though.
I say if you love him and you know In your heart that hes the one and only then liston to your heart. Even if things don't work its a wonderfull experiance and hopefully he will always be apart of your life. It does seem like you are looking for a reason for it not to work enjoy it while its there.