Sorry not to have replied before, I was working yesterday and very late home.
At this stage, I would be more concerned about treating the PND that SS being involved. You say they are ready to close the case, so, to me, that suggests they are happy with how you are doing prior to the PND. Please see that as a positive.
Did you get to see the gp or HV yesterday?
Whilst your living conditions aren't ideal, at least whilst you are with your mum you aren't worrying what is happening between visits to her. I remember when my nan was very sick, my aunt lived 2 roads away and was popping in at least 3 times a day, plus visits from meals on wheels and various cousins. If you moved out, do you have a plan to deal with your mum's care?
I'm really sorry, but I always try to find something positive about every situation, and focus on that. I know you will be finding this hard at the moment.
Part of the situation, your DH not wanting to talk is just the difference between emn and women, it's frustrating, but it isn't going to change much. If you focus on what you can change, then you will be able to see the results.
You mention that you are starting to argue, maybe it isn't you that is changing. You are now dealing with a mini person with his own opinions, that isn't always easy. I have 3, DC3 is currently 2.7 and at this age you can't reason with them. She has more tantrums in a day than the other 2 ever had. It could just be your 2 yo is now pushing the buttons.
If you find you are losing patience, put him somewhere safe, cot/playpen/in front of the tv and take a cup of tea outside, give yourself 5 minutes to calm down, then go back, hopefully refreshed. Welcome to the world of 2 year olds.
You mentioned Losing patience with your mum. She is probably finding it hard having to rely on you. Do you get any support at all? Perhaps you could raise this with the gp as I suspect you are exhausted and that and the PND may feed each other and put you into a spiral.
I wouldn't worry about your mum having a different idea about DSs behaviour to you, there are loads of threads on here that can show you how normal his is. My PIL were always telling us we were too hard on our DC, but then they tell us how beautifully behaved they are and how much PIL love to spend time with them. Do you think here could be a reason for this? It is really frustrating, and arenting has changed since their day, and they forget how hard it can be.
Please go and see the GP, ask for some medication, abbé some counselling, ask for some help with your mum so you get a little respite, even if the help is only temporary, to help you get over this.