I have read many, many appeal decisions. This is my advice based on that and on my own appeal.
1. The appeal judge usually does not believe the sponsor and applicant when they start complaining about how they were mistreated by people in the visa office. My advice is do not even bother talking about this. Anything you have to mention to tell your story, do so in a neutral way. Your case is very upsetting and stressful, but talking like you are here in court will not help you.
2. Get proof of anything you say. You should be able to get some proof that you were working where you said you were; at least an affidavit from the boss or a coworker.
3. Is the appeal because of the misrepresentation? Or is it also because they do not believe your relationship is genuine? If it is both, get evidence for both, and present both aspects separately and clearly. That is, prove you did not misrepresent yourself in the TRV application - again, an affidavit from your boss may be enough. Then present proof that your relationship is genuine. It sounds like you have a lot of that type of evidence.
4. The MP assistant who suggested you apply for another TRV did not do anything wrong (unless I am missing something). This was a valid suggestion, which unfortunately did not work out in your case. It is also irrelevant to your appeal. At the appeal, if you are asked why you applied for another TRV, you can say because you really wanted to see your husband. You can also mention that an assistant to your MP suggested it might work out this time - but you could also omit this. Applying for another TRV is OK, but you should be clear that the reason was so you could visit your husband.
5. I do not know who you were thinking of taking to court, but it will be a big waste of time and money. (Especially if you were thinking of suing embassy staff.) Concentrate on preparing your appeal.
