Stressed out mare

[Acrispul W]

Hi all,
I've recently (about a month ago) had to move yards with my mare. Since we've moved my calm chilled out girl has gone from happily spending all day in the field to stressing out the moment the head collar is removed. She has been galloping the fence line and working herself into a foaming mess. She has so far not tried to jump out but I'm terrified if she's left out for any period of time that she will try. I've tried swapping fields, but the situation is the same. I've tried standing with her on a lead rope for half an hour or so and unclipping it once she is grazing but the moment she hears the lead unclipped she runs for the gate. I've also tried giving her her feeds in the field. She doesn't share the field with another horse but she does have neighbours who she could touch if she wanted to.
I dont know what to do, it's horrible to see my girl so stressed out and I'm not sure why. I have put her on a calmer (pro-kalm) on the advice of my vet but it doesn't seem to make much difference. The only thing my vet has suggested is to sedate her but I'm not sure that would help.
Does anyone have any ideas I could try?

I should add that she is better in her stable, although not totally settled. She is eating normally but does seem worried about what's going on outside.
Thank you in advance for your help

 

[Apercrumbie]

Was she on individual turnout in her previous yard?

 

[Acrispul W]

Yes, she has been on individual for the previous 6 months. Before that she was on pairs

 

[Meowy Catkin]

Yes, she has been on individual for the previous 6 months. Before that she was on pairs

That might be the issue. When she moved to the last yard, she was in a pair so she had that other horse to help her settle into her new home. When she was moved to individual turnout at that same yard, she was settled there so it didn't set her off fence walking etc... However she has now moved home and doesn't have another horse with her to help her settle. This appears to be too big a change for her.

ETA - could she be put in with another horse/pony or herd (sensibly introduced)?

 

[Acrispul W]

ETA - could she be put in with another horse/pony or herd (sensibly introduced)?

She was turned out next door to another horse in the hope they could eventually be turned out together. But she doesn't show any interest in them, just panics and paces the fence line. Now that the YO has seen her behaviour she is reluctant to turn something out with my mare in case it upsets the other horse.which is understandable, but does make things harder.