seems like to me ur living in an uncertain future.. in other words ur just worrying and thinking 2 much in the future.
the best advice i can give u is to not worry about the future, cause that will come around soon enough. and when it does u can deal with it then and there. so pretty much just live in the present. enjoy being with ur boyfriend and brush aways those quite nasty thoughts. because if u truly enjoy being with ur boyfriend it only makes sense to enjoy it, so why doubt it?.
also being able to trust ur bf would help. i mean if u don't trust him of course ur goin to worry. thats natural. a healthy relationship is usually built on trust, well so i've been told.