@ASDADDY I could have written this! Honestly I don't know whether it is possible to work out which bits are trauma and which bits are threenager, but I do know that what I experience is that his behaviour is that bit more extreme, that bit louder, that bit harder to manage than his typical peers. It is bloody hard work, and ceaseless, which I find myself explaining to people because he can be so lovely and is infinitely loveable lots and lots of the time. It's only when I write down everything that happens in a day that I begin to realise the severity of the behaviour. I would strongly recommend keepinga diary of a typical day or week to take with you to meetings.
Nursery staff will probably not know much about trauma, very few school staff really do unfortunately. I found the Coventry grid a helpful document to share. It shows the differences between asd and developmental trauma.
Someone once told me not to allow myself to become the only expert in my child, and sometimes you do need to just let you other people make their own mistakes and forge their own relationship too. It can be difficult to step back, but sometimes very very necessary. Also, if your partner is frustrated, that's OK. He is allowed to be frustrated, but it doesn't mean he gets a pass out of dealing with the behaviour. It means he deals with it and is frustrated, which you can explore later, but for both of your sakes, you both need to deal with stuff in a way that feels equitable and fair.
In terms of strategies, it is worth tracking any changes and getting on a road to get help ASAP, and to be honest if they are suggesting adhd and asd amd are willing to refer you to get that help, i might be inclined to "accept" it and then use that referral to speak to someone who knows their stuff, rule those things out and then those professionals will be able to refer you on to someone else who can deal with it. I always reckon an Ed psych is more likely to be more knowledgeable about trauma and have better resources than a classroom teacher, so whatever gets us in closer contact with to those professionals is worth doing. We have started down some routes to try and get a diagnosis or help now because although his (AS 3, nearly 4) behaviour is just about manageable, it won't be if it continues, and so it is worth looking up stuff now because lists are long and things can change rapidly. You want to be able to say you have already ruled stuff out.
You sound like you are doing an awesome job. It's bloody hard, and there are so many conflicting emotions going on. I suspect getting your partner on board will be crucial, if only to stop you being the default parent and having to take responsibility for what can feel like a mammoth task.