You know what? I felt the EXACT same way you did when I first saw MF. I got SOOOO freaked out when I saw it...it was SOOO big, and SOOO intimdating...
But you know what?? Think of it this way (I did): Is it worth it to just wander around, wondering what the ride would have been like, staring at it, deciding to go on, then not...etc etc?? It's not! Pretty soon, time will go by, and you will have missed your chance. I know, because I felt the same way when I went on my first coaster. And now here I am, a coaster FREAK!
My advice to you is to just ignore the height. Forget about all of your fears, and just go on. Force yourself. Really, MF is a FANTASTIC ride, and if you like rollercoasters, this is THE one to go on! The first drop is not bad...it is VERY far from bad!!! It is THE greatest drop in the history of mankind...u a Gemini freak??? Think of it this way; MF will be Gemini times, ohh.......about 100!
Seriously, just go on! You'll WON'T regret it!