
I really feel for you and hope my experience helps.
My abusive ex-husband (of 20 years) was a high-ranking police officer.
On the day he received an award for bravery from the chief constable, he smashed up our house because I did not dress 'sexy' enough for the ceremony. He was/is also an alcoholic, which was kept completely hidden from his employers. I'd also describe him as charming, very clever and completely convincing.
The first 3-4 years of our marriage were the only relatively happy ones; he was emotionally abusive, but as a teenage bride - he was mid-twenties - I had no idea this wasn't normal behaviour. Then he had his first (of many) affairs and the abuse escalated.
I'm from an exceptionally traditional family and did not even contemplate separation or divorce. I would still be married to him now, except he became abusive for the first time ever in front of our child. Something inside snapped and I knew then our child came first and I would never tolerate that behaviour ever again.
I had to call the police that night who were exceptionally shocked; they were coming to deal with their drunken boss. He was removed and charged and an immediate restraining order was granted.
Character reports were used in court - I did not recognise who they were talking about. Likewise, they had no idea about his drink problem and what my ex was like outside work. I didn't think of it as lies - to them he was a great employee/officer. They had no idea what he was like because I'd never reported a single instance of his abuse before. He said no-one would ever believe me if I reported him. He frequently smashed up the house, destroyed both my confidence and my property and threatened to kill my pets.
My ex also had statements from medical professionals, stating he had PTSD through dealing with certain cases at work and citing childhood abuse (which he hadn't told me about).
Courts are not emotional places - they deal with evidence. You have his abusive emails over time which is great; he can't claim his abuse was a single 'moment of madness'.
You/your solicitor could also get personal character references. People you work with are allowed to do this in a private capacity, you don't have to ask the permission of your employer. The only time you would need to do so is if the character statements are on company-headed paper.
Can your G.P. also provide a statement regarding your PTSD and the reason for it?
As your employer is being so unsupportive, you could have a very strong claim for constructive dismissal. Are your legal costs covered by your house insurance? Many people have this cover without knowing. It might be worth investigating? I'd also ask your G.P. if they could sign you off work.
In my case, previous service record and character witnesses counted for little - my ex received a 3-month suspended prison sentence and is permanently blocked from contacting me directly or coming within a specified distance of my home or place of work.
It's not been easy - my ex was SO convincing not even members of my own family believed how serious his abuse had been, never mind his family.
You can deal with this and be a much stronger and happier person as a result. Best of luck