What is asexuality?
Asexuality is a sexual orientation characterized by a lack of sexual desire. Chastity or absence are not the same things because they are choices not to have sex, asexuality is not wanting to. Asexuality is also not the effect of a drug or aging, it is just the innate lack of sexual desire.
Am I asexual?
If you experience a lack of sexual desire then you may be asexual. Even if you masturbate or have fantasies, it doesn't mean that you aren't asexual, it refers only to sexual desire. Ultimately it comes down to how you feel. How you identify is the most important thing.
Can asexual people love?
Asexuality only refers to sexual attraction, not romantic attraction. An asexual person is fully capable of love and many of them are in happy, loving relationships. Some asexuals that also identify as aromantic may not feel romantic love but that doesn't mean that they don't feel love such as love for a pet or family.