I remember I went on ToT when I was 6 yo. and was terrified to go on it again! At least until this past summer. I was forced on by some friends from the DIS

, and I am so glad they made me go on! It really wasn't as bad as I thought/remembered.
I was terrified! Completely! I was shaking uncontrolably and thought I was going to freak out! LOL.

But, it felt SO good when it ended, and I realized that it was actually an AWESOME ride!

Of course, I screamed the entire time (unknowingly) and I think it took some of the feeling away.
Also, a piece of advice I don't has been mentioned yet, is to LEAN BACK! On both Splash and ToT. The best thing to do is put your hands up (almost completely gets rid of the feeling), but I still have not built up the courage to do that yet

.
The further back you lean on Splash, the less of a stomach feeling you get. I love Splash Mountain SO much, and could never go to WDW without going on it! I have gotten so used to the drop now, that I can actually stage a certain pose for the picture. (Like last time, I pretended I was asleep. Stupid, I know, ROFL!

)
With each of the 8 years that I went to WDW without going on ToT, I kept thinking that if I went on it, I would get sick, because I couldn't stand that feeling. Had I known that Splash Mt. had more of a stomach feeling than ToT (which it does, at least for me), then I would have gone on ToT in a heart beat!
Good luck with conquering your fear! I promise it is totally worth it!