[younghorsetrainer]

Oh dear, I am sorry that you are going though all that!
That is sort of what happens to me different times. I know how discouraging that can be with horses sometimes!!!
I had a similar situation with my black horse. I was keeping him in a farther away pasture with a buddy of his and riding my other horses more than him so I only rode him for a short ride like once a month.
Then after a few months I noticed that he was getting very very balky. He still hasn't gotten over his balkyness 1 year later but he is much better. I find that the more that I ride/interact with him the less balky he gets.

I think that not really riding him for months made him like that. If you didn't ride Sugar very much for a few months that would be the case. I have found out that riding at least once a week keeps a horse from getting very balky and riding a few times a week is even better.

This sounds like the exact same thing with Castillo as with Sugar. It would probably work out for you to-when you are out on a ride, and she balks, ( stops in the path for no reason) ask her to go on, squeeze, cluck, whatever you normally do, if she doesn't go on giver her a smart smack with a little willow twig that doesn't have bumps, or a riding crop.
If she still doesn't go on she is really balky as was what Castillo did. If she still doesn't go on cluck squeeze wait for her to go on like 3 seconds then smack. As soon as she steps forward instantly release, even if you feel a small leaning to go forward.

You might also try not making your training sessions all the same. ( I don't know how you do it but here are some tips)
This works if you have a lot of time and be patient, this varying has to take place over a few weeks for it to sink in very well if you keep varying a lot all the time.
I like to vary up my training sessions so your horse never knows what you are going to be doing next. Like you could..... ride for a long time and you could stop and rest for a while in the middle of the ride, another day get her and bring her to house/barn and brush for a long time do some groundwork and then let her go ( she might be surprised that no riding) one day get her saddle ride around for like 5 minutes unsaddle then let her go, another time you could saddle her and lead her on a " ride" another time you could ride somewhere with really nice grass if you have places like that, picket or tie up and let her graze for like 30 minutes, just basically varying your interactions with her a lot but do that a lot not like 2 days a week.

Sorry for the long reply lol!
Good luck and I hope this helps! 🥰 🥰

 

[younghorsetrainer]

I'll also add I can't ride in the fields because they are so hilly and bumpy

A quick question, why ^^^^^? Not to be offensive though. I think that riding all over the place is excelent for horses and hillwork is very good for them and the bumps, well it is part of the fields. If you ride on a smooth trail or an arena all the time all the horse see's is a smooth path and not a pasture like they stay in when you don't use them. Maybe you could try riding in the pasture that you keep Sugar and Skye in.
P.S. We have small " trails" in several places where there is a path through woods for like 100 mts longest or like 20 mts usually and the horses are glad to get off the path on onto the rest of the ride though the pastures like usual. They don't like paths very well unless they are short ones.

 

[younghorsetrainer]

I kind of meant I can't ride there doing circles and working on flying lead changes and all the stuff we used to do. If we just go in straight lines and do big circles it's fine. I'm just a little weary that she might trip and fall on her face if we were doing harder and more difficult work on the bumps and hills. I don't know, I may just be overthinking that lol.

Oh I see now! That makes sense, it isn't the greatest place to do arena work out in the fields lol!