Thank you for the replies.
Yes I'm leaving- same (very large) employer but different site.
The person in question used to be my friend but work situations have quashed that (for me, I think she still thinks we are mates, which is part of what is making me I'll as I have to tolerate her presence on social media etc. when I leave I'm deleting her but until then I need to keep her sweet).
She is my line manager, we used to be peers. She was given a temporary promotion for a job that I desperately wanted. I didn't even get the chance to apply- it was handed to her on a plate despite her lacking in any relevant experience (of which I had years).
I had to suck it up, smile sweetly and get on with it, hiding my desperate disappointment. I licked my wounds for a few months then decided I wanted to properly try for progression and for three job offers (all same large employer)- two temporary and one permanent. I took the permanent one so that I could sever ties completely. That was about a month and a half ago.
Other things have happened since which have caused my overall resentment to grow, not directly related to her.
Our employer can keep your for around 3 months before letting you move sites, which they are doing. This interim period is driving me up the wall.
I've realised how much I have resented her, her lack of experience and her line management style. I have been mainly very supportive and very helpful to her, teaching her a lot about the job. I accepted that because i always work hard, do my best and as she is my line manager, it was always in my interests to keep her onside.
But since I relieved that first job offer, something clicked in my head, I signed out and I can no longer keep a lid on my emotions. I don't want to get a bad reputation or go out on a low but the stress is making me quite ill.
I also feel unrealistic expectations are being placed on my last weeks- I'm supposed to be doing all my usual jobs, writing a handover for my replacement, developing my team at full pelt and even starting new small projects.
I rang our employee helpline and scored too highly for their help. I have had CBT before and am trying to use their techniques, have self referred again with my GP for CBT (but that takes ages) and am doing all sorts of reading etc.
I have also asked to arrange a meeting with her to discuss all my concerns and the thought of that is making me ill. She brought our friendship into it the other week and said she knew why I was horrible to her sometimes! (I'm not but have lost my temper a couple of times since knowing I'm going- no swearing or shouting, it was more that my sweet facade has dropped and I've become non compliant. I hate being like that- my nature is to be a compliant hard worker who does what my manager tells me). 🤯🤯🤯🤯