There are quite a few things you can do, if you set your mind to doing them.
What I'd say is to start small. Start with something like E.T, then pat yourself on the back for each new thing you try. Mentally: If I could do THAT, then I can try the next thing.
Keep in mind, each ride is only a few minutes long. You might not love each one, but it is only a few minutes long.
Another option is to re-ride the attractions you enjoy. Like for MIB go again to raise your score.
In my opinion, Slinky is more intense than 7DMT. The reason you may have found 7D more intense is that the front of a coaster is almost always tamer than the back seats, unless the ride goes backwards or something unusual like that. You can usually request to sit in the front seat. (Or near the front, if that is easier.) Most enthusiasts prefer the more intense rear.
If you dislike 7D, then Hagrid's is probably a bit much for your first day. On the other hand, ride fear is often mind over matter. One calming trick is to count in your head, especially during the intense parts. If you know the 'intense' part is only 4 seconds long, then you have control. Often fear is about lack of control. So the trick is often to find a way to gain control.
So like on Test Track, you probably were okay on most of the ride, just not the last part. So one way to gain control is to focus on the parts you like, and keep mentally minimizing the small part you don't like. The 'fast' part is just a short part of the ride.
The more times you conquer any ride, the less you will fear it. So if you find a ride you can 'tolerate,' consider re-riding it - perhaps even right away. the idea is to de-sensitize yourself over time.
I think it also REALLY helps to be well hydrated. not quite full, but not empty stomach either. If ever ride intensity/spinning starts to get to you, sometimes a little sugar helps. Gummy bears are great for this. (though maybe not while ON a ride.)
Also at Universal, consider the non-rides. I highly suggest getting one of the interactive wands after seeing the little wand show. Well worth the $, especially if you will be returning to US. Universal also has some neat gift shops. There is one.. I always forget exact location, but it is near the Horror make-up show, and sells props. Fun place to look.
Another option is to convince yourself to walk through just the queue of every attraction. You can then request the chicken exit. The more times you conquer a ride queue, the more comfortable you'll be with that space, and in many cases you still get to see some really neat stuff. I highly encourage you to do this for the new Velocicoaster. Exit when you get to the lockers. But DO see the animatronic dino in the queue. Hulk and Dudley queue are not exciting, but Velocicoaster is fun to see.
For Minions, you can request stationary seating. If you mention it right away (to front staff member), you will likely be directed to side entrance, which has a MUCH shorter wait. For Jimmy Fallon, closing your eyes solves much of the motion. Again though, the preshow is worth your time. It is almost the highlight of the show.
You can likely handle Spiderman. It is a really neat ride. You'll also like the Hogwart's Express- in both directions.
Smaller Hippogriff and Woody Woodpecker coaster are almost IDENITCAL to Goofy's Barnstormer. They are both small and very short rides. Hippogriff is slightly more intense, but the scenery is SO cool! And very much a kiddie coaster. Tamer than 7D/Slinky.
In my opinion forbidden Journey is a bit intense if you have motion sickness. There's one part where your cart really tips. It is mostly slow moving though, and much of the motion is via screens, so you might tolerate it. DO see the queue though, as that is really a highlight of the attraction.
Oh, at Universal, if you don't want to ride, many rides have a waiting room at the top of the queue by the ride. That is how they do child swap. It is different from WDW. While you are not riding, you can at least sit in AC room. It also might make it easier for your family to ride without you + have a very easy way to meet up after they ride. (I think they will let you use the room without a toddler companion.) On a few rides, like Hulk, you can maybe help family avoid the lockers by holding their stuff. You can go on the nearby teacups (called Storm Force Accelatron) while they ride Hulk.