Not too long ago I was struggling with concepts of love myself... Once I detached it from romance, I pretty much realised I identify as poly.
Love for me is a special connection, but it can be of any type. There are people I love but have no particular interest in having sex with, or dating, although I love their company and may or may not have physical affection with them.
I love my family unconditionally. Marriage, for me, will come when I love someone unconditionally and want to make them family to me (as a spouse) and make a family with them (through having children). This will not affect my love for others, nor would I ever commit just because I like/love someone.
I love my cat. This love is also unconditional, as well as affectionate.
I don't love all my friends -- hell, I don't even necessarily like some of them! But there are friends I love in terms of fondness and simple liking.
Sex, on the other hand, for me, is either a physically enjoyable activity, or a form of connection and/or communication in itself. I can love without sex, and I can have sex without love.
Love has so many forms and it no longer matters to me what it means. It can mean very different things depending on the person/animal/thing in question. I only say "I love you" to someone who knows in what way I mean it for them (except for my cat. Pretty sure she doesn't understand it at all!