My horse was like this when I first got her. She always bolts if she is facing one way (facing the rest of the horses outside) so I turn her around so har butt is near the other horses and her face is looking out the screen door so she can look at birds/cats/field. Not sure if you can do this but that really helped for my mare. Then I slowly started to build up her tolerance. I would bring her in and as soon as she got antsy i would lead her outside before she could bolt. I would do this to show her that everyone is still outside and safe, and then I would bring her back in. For the first few times on the cross ties try not brushing or tacking up, just have treats to keep him distracted and then after a few minutes lead him out and he will realize that nothing happened while he was in there.
If you stall your horse you can try cross ties in the stall. For many horses a stall can Ben a comfort place there for calmer.
My pony used to break the crossties constantly, so what I did was always talk to her in the crossties, and make sure she had something to keep her mind busy so she wouldn’t run out. It is hard and took a very long time, and now she is only scared of one crosstie stall in particular. Another thing I did was have her stand in the tack up stall with out putting on the crosstie and just have her stand there for a minute, then reward her, then put on one crosstie for a little bit, then reward her if she did good, and finally put on the last crosstie for a longer time than the other 2 and reward her lots.