It took me about 5 years and 10 trips of trying TofT before I finally decided that I liked it (granted, I was about 8 or 9 when I changed my mind, but still). You gotta try, though, because you'll never be sure when you'll like it. As much as I hated it as a kid and as many times as it put me in tears, now I absolutely love it. We usually head to DHS first, and part of the reason is that I'm not settled until I've been on TofT and Star Tours, so I enjoy my trip more if I get those out of the way.
In TofT, after you get into the elevator, you go up, then up again, then you go forward. Then you'll hang there in the dark for a second, and you truly won't know whether you're going to go up or down first. After that, although the drop sequence is random, you'll get a sense of when you're going to drop.
I get motion sick, and TofT does not make me motion sick. Astro Orbiter is a huge no-no for me because of my motion sickness. If you start to feel disoriented, look up. You'll be able to see the ceiling as you move up and down.
I'm a bit of a daredevil, so I've been on rides that are much worse than TofT, so I'm a really bad judge of how intense the drops feel because for me, they're fun without being too intense, but my opinion isn't necessarily that of everyone's. It's one of those things that you must just try once. Especially since many, myself included, consider it to be one of the best rides in WDW. If you hate it, then don't do it again, but if you don't try it, you're really missing out.