First, consider finding a teacher or mentor. This is exactly the sort of question where someone experienced can greatly help. Of course finding such a person with whom you "connect" may be difficult. Even if you can't take regular lessons, it is very valuable to have someone to reach out to occasionally who can see your playing and knows a bit about you specifically.
There are a lot of of online courses and even entire books with videos, etc. that layout specific lesson plans and such. I'm not a big fan of that sort of thing, but I've never been one to study things in a strict order.
One thing that is difficult, but important, is to get out of the "speed" mindset. It is tempting to think of speed like strength, a thing one can build muscles for or train for as a single metric. In practice, the tempo one can really play well at is the combination of a lot of different skills and any one of them can end up being the limiter. Progress will be best when practicing at a tempo where you have complete control and are playing without tension. This can be frustrating as often one can crank the metronome up and still be able to play reasonably, but it is less effective to practice at the hairy edge of what you can play correctly.
Single exercises to develop speed are useful when you know there is a specific localized weakness, or when beginning and all exercises lead to improvement, but as you get better, you'll need more complex exercises to move forward. In as much as you are feeling plateaued, it might be good to work on some things you have not yet worked on and possibly combining multiple skills into a single exercise
A number of these items fall under the general heading of "independence" -- being able to do arbitrary things with all limbs simultaneously comfortably and without tension or undue mental effort. Try playing combinations between the feet and hands to develop both strength in each limb and the ability to use all of them together. Rudiments such as paradiddles can also be applied across any two limbs, and are often the underpinning of another exercise.
(There are many reasons to practice rudiments, but my experience is they're a long term investment not a thing that leads to overnight improvements. I'd consider setting aside a fixed time per day, perhaps as little as 10 or 15 minutes to practice rudiments on a practice pad. You can just work through a list of rudiments or use a book like Stick Control or Funky Primer for the Rock Drummer. It is actually kind of hard to get everything you should out of this kind of practice without making very sure you're doing the exercises correctly. A teacher really helps.)
I use Polynome, an iOS app which lets one program up a variety of patterns and then keeps track of how long one practices. One can also look at tempo progress and such. I find this gamification of practice quite useful. Though in and unto itself this will not tell you what to practice.
Playing with others can also be a great motivator. There's a huge difference between playing in a band and playing along to a song or a metronome.