God this sounds like a nightmare, I have been there OP, I was micromanaged a long time ago, by someone who totally lacked confidence in their role and took that out on me. I left that job in the end, but I do sometimes wish I'd dealt with it formally.
I used to be a union rep in the public sector and this is how I would deal with this case, as you've already submitted the grievance.
I would email HR, copy in her manager, and their manager, and state the following:
That someone has informed her you went to HR putting you in a very difficult position and breaching your confidence.
That as a result you will no longer be prepared to participate in 1 on 1 conversations with her until the completion of your grievance and any subsequent appeals and disciplinary procedures are completed. Either someone else takes over managing you, or someone shadows her or chaperones you in any meetings with the two of you.
Also I would ask if HR could confirm the timescale for resolving your grievance.
That your prefered resolution to this situation is that one of you (preferably her, why should you have to move?) move teams.
I would also note that she has suggested that you take your laptop to the bathroom in order to be permanently available, and that not only is this impractical, but that you have a right to dignity at work, and privacy in the bathroom, particularly your own bathroom in your own home, and as such this suggestion is wholy inappropriate. That alone should be a disciplinary matter. As such I'd request a copy of the Dignity at Work Policy (assuming NHS, there should be one) and see what further complaints I can build based on that.
There's nothing stopping you writing an email like the above and sending it off. You would have an even stronger case for complaint if you suffered negative consequences as a result of complaining about bullying.
In terms of leaving your role, and whether she could stop you getting a job somewhere else, it depends on the industry to an extent, but it's unlikely. For one thing you don't have to put her down as a reference, just give the details of your HR team, they will provide a reference if needed. As far as a new employer is concerned, she doesn't exist. So don't let that worry you.