no need to feel like an impostor. you could be homoromantic asexual. or if you're also on the aro spectrum, oriented aroace (where tertiary attractions are relevant enough to be considered part of their orientation) could apply.
even if you're not on the end of the ace spectrum, like gray or demisexual, you still belong in this community. and if you ever turn out to be not aspec anymore in the future, i'm sure you'd still be welcome here.
you are what you are, and that's valid. you don't need to prove your place here.
and feeling lonely/sad because you don't have anyone is no reason to be excluded, either. some aces (and aros) have no problem being alone. some crave a relationship of some kind. some are actively avoiding it, because "ew, relationships".
the ace spectrum is just as diverse as humanity itself, we just have the little difference of not (or conditionally, or rarely) experiencing sexual attraction. that says NOTHING about our opinions or how we interface with the (lack of) feelings