UNconditional Love

I do not know anything about love.

I'm single, always want serious relationship with the one. I'm tired of freaking out to be left and i'm lonely, hard to admit but yes i do feel lonely sometimes.

Is it so hard to have unconditional love?  why is it called love when its conditional?

Have you ever feel terribly mad when you feel like you do everything for him, but you think he/she's not?
Is it called conditional?
When he/ she does something that really doesn't come from his heart, do you feel like crushed? can you still love him/ her?

Anyhow.. at this point I really don't believe in anything called true love, except love from God.