I don't know where else to turn?

I'm 15, and it took a great amount of persuading to get my rather large, over-protective parents to let me date an 18 year old, who I've grown to love and respect more than I thought I would. Well I was with him last night, and today, in the car, my hair was tied back, and my faithful Christian mother happened to see a hickey that apparently I didn't even know was there. My boyfriend and I did not go past the neck, and my mother is making a huge deal about it. She told me that she'll never trust me again (I've made similar mistakes with a past boyfriend), She'll never trust my boyfriend again, she doesn't even want to look at me, and just blowing things way out of proportion because she thinks we're having ...which we aren't, and even if we were, is it right for her to throw a tantrum like a 4 year old? Shouldn't she calmly talk things out with me? Let me explain myself? I tried to lie at first about it being a hickey and she told me to either tell the truth or face consequences, so I told the truth, and she's throwing a fit, and I swear to God she's going to make it impossible for me to see him....Isn't she kind of a hypocrite? Act like she's gonna be all accepting if I tell the truth and then punish me when I do? Should she not allow me to see this boy? I need some serious advice....Please, no "You're too young to date" or "He's too old for you".....I understand where you'd be coming from but I've already heard this, I don't care if he's a few years older, love overcomes age, and don't tell me it isn't love either, I've had to put up with alot of crap from people to date him. I've had to sacrifice alot, and so far, he's the only person I've met who actually makes me feel wanted...Like I belong here...So please, I don't know where else to turn, I feel if she makes it so that I can't see him, I'll have no one, because my whole family looks down on me now for this hickey, and my friends aren't supportive or helpful at all...I need help...I feel like everything good in my life is disappearing :'(