Abusive boss ignored by firm, need advice on protecting a pre-COVID19 job opportunity?

Working at a BB in RE investment, worked in MM REPE prior and did well in that role. Currently the only person working under a Director who is mentally and emotionally abusive, and who thrives on publicly executing others for their shortcomings. Outwardly the people working in their sphere greatly dislike them, but this person manages up very well and can be objectively classified as very intelligent and good at their job, so it’s overlooked. Naturally as the only person who works with them I’ve gotten the brunt of it and find myself becoming jaded and indifferent towards a workplace with no hope of promotion or even a recommendation letter - not that I would solicit one. At first I was really concerned that they were right, and I really had no idea what the hell I was doing but I found out from other employees that this person has had four associates for one position in two years before me. It’s now been 18 months in this nightmare, I have great standing in the firm with this person aside. I was in the final round of interviews at a public REIT with indications I was the favored candidate and got frozen in the hiring process following COVID19. I’ve reached out but HR really has no idea what will happen yet. I don’t want to lose this job when this is all said and done so I can light this bridge on fire.