I also felt asexual for a very long time. I never felt any "spark" until I was almost 25. Even then it took awhile for me to get over the "icky" vibes and feel at all comfortable with the idea of sexuality, affection and vulnerability. There were a lot of things I considered kind of boring or gross at first. And it was really scary to be dating someone.
Eventually all that passed, because I loved him and do love him, but if we end up going our separate ways (god forbid...) I think it's possible I would have the same issues all over again.
Anyway, I think sexuality is a very broad category and think that asexuality does exist in varying degrees. Romantic v. aromantic, people who are repulsed by sex and people who are indifferent to it....I also think many people can learn to enjoy it with somebody they love, but are totally turned off by the idea of doing it with strangers or people they don't care about (I would fall in this category). I am very comfortable with my SO now, but the thought of sex with other people brings back the old "ew" thoughts. I can find people physically attractive, but have no sexual desire towards anybody but my bf.
OP, do you think you will ever want to "experiment" with your (a)sexuality? Do you wonder if it is possible you might find someone you would feel comfortable having sex with? Or do you think your sexuality (or lack thereof) is firmly set at this point?