Seeking relationship insights in an unpleasant work situation

[BugEyedBeans]

A work situation is increasingly difficult - really unsure how to proceed.
My organisation has one major funder and i have to work closely with their representative. Of course there are the normal ups and downs in this partnership but I am increasingly feeling this person is targeting me - alone among all my team - for everything that he perceives as wrong. It almost feels like the early stages of an abusive relationship, building up.
So when there is an important event coming up he gets very stressed and picks fights with me over minor issues (can't say what - too outing!!) and then escalates them - and then this casts a cloud over everything my organisation does.
I just don't know how to behave when this happens. I have tried to remain professional, but now, as well as cutting me out of some important discussions, he is starting to tell me what to do - which is totally not the professional relationship we are supposed to have.
Another bit of the jigsaw is that he feels that he has to do everything himself and that I am unhelpful and obstructive.
Seriously my approach to work is collaborative - i am so not interested in petty time-wasting feuds - I understand, I hear that not everyone is like this but have never experienced this in any other workplace. I can't "LTB" cos he is essential to our work - and I can't complain to Directors because that would look like I am not managing the situation in the interests of the business.
Unfortunately I'm also becoming very stressed and anxious about it, the situation is genuinely pressing my buttons!
I just wonder if there are insights the relationship gurus may have?

Don't have any experience of exactly this type of situation, but generally I would say when having problems with colleagues it's best to call them out on it. If he tries to make out that something is your fault then politely but firmly point out that it isn't/say what really happened.

Don't just let it go and then worry about it - it will all become very stressful and he will see your lack of response as a tacit admission of guilt.

Always better to face down a bully!

Ahhh I’ve been there. It’s hideous. First of all, you’ve got to get the first punch in. So, either have it out with him (which by the sounds of it he wouldn’t take) or hand the account/relationship to someone else. But make sure you drive it, not him. Even if this means that you’ll feel that you might look like you’re not handling it, you actually would then be being proactive in maintaining the corporate relationship, rather you having to take one for the team if and when they take their business elsewhere. I can’t stress enough how important it is to throw this hot potato away ASAP.

By way of illustration I picked up an account for a colleague who was in this situation. She just clashed hugely with the main person. She was very details, he was big picture, etc. He wasn’t expecting to be suddenly given a new contact and I made it clear that it was as a result of my colleague’s unhappiness with the productivity of the relationship. He was a bit rattled as he didn’t want it to get back to his boss that he was getting this so wrong, and actually we got on ok. I really admired my colleague for handing it over and saying “this one isn’t for me.”

Like the advice above. In my worst work situation, have been asked in hindsight what I would do differently. Leave! I’m shut st dealibg with big work probs, alternative is patience. The problem does go away when your right x so leave or patience, the problem is going to do what it’s going to do