not sure if this is where i post this but i’m a new guy. bought a 20" torker dx. got about 3 hours in the saddle. i’m an avid road biker and enjoy distance runs, but man, this thing is kickin my butt!!
all i can say is that you need to just keep practicing, I think it takes most people about 10-15 hours to ride.
I was in your shoes (“cleats?”) at the beginning of summer when I started learning. I used to race bicycles on road and velo for a couple of teams in my area and did pretty well. Then I sort of drifted into racing long-distance events for fun.
I started leanrning unicycle just because it looked like a fun and different way to get a workout. I’ve been at it for three or four months now, and I have no problem commuting to work in traffic (12-mile ride) and I’ve done a couple of 20±mile rides so far. Here’s the deal: in the beginning, it will feel f-ing impossible! But if you just keep riding, you gradually get better and better. No secrets, just lots of saddle time. The workout itself is weird: less directly aerobic and intense, but it definitely works you. Right now, given my skill level, a 20-mile non-stop ride sort of duplicates the bicycle century ride experience, only in a much shorter time frame…that is, the first ten miles feel great, the next 5 are work, and those last 5 are some serious effort. 
I cruise around 10 miles / hour on my 29" wheel using long cranks, which is half my average road bike speed for regular bike workouts. As I’ve mentioned in another thread, I don’t mind spending twice the time, because riding the uni is at least twice as fun!
I would suggest that you move up to a bigger wheel as soon as you can. I think you really need at least a 29" to use the thing for practical transporation.
Stick with it! I’m a 53-year-old geezer, so if I can ride the thing…well, you know…
well, i got about a 1/4 mile and think i got the going fwd thing down pat. just need more practice, need to learn how to free mount and need to learn how to idle. gettin there though! diffidently need a bigger unicycle though… this 20"er creeps