paranoia and unreasonable arguments

Hi My husband is causing arguments in order to record them without my knowledge and definetly without my permission We split up for 4 months and it would seem from what I'm piecing together he didn't have enough conclusive evidence to take the children (both autistic, whom do not like being with him on their own because of his lack of patience etc.... So he has since his return to the home been instigating arguments and dropping weird and wonderful in factual and some times downright lies in the on occasion I have responded (I'm the one who reacts to the heat of the moment person who at the etime fully means everything they say...However I am scared that if he plays his scripted arguments we will loose are girls...due to his paranoid behaviour... At present focusing on xmas but if anyone had any ideas as it always seems it's me having to give in and be the adult....don't treat him like a child... Advice please. .. I have PTSD and 2 autistic girlie's and a husband who had a bang on the head and since then as months have turned into almost 2 years now has fill blown adhd....lost my soul mate and have a stobborn childish argumentative person who looks a lot like him but certainly where all resemblances end..... UK so diagnosis but no help.for us the victims sorry family!! Presently not responding to his plan but so terribly hard not to... But this is like holding everybody's happiness in my hands and it's getting too much responsibility and I old....don't even have any fun as scared that he will do something that will spoil it like he used don't seem to notice and neither do his friends but His self medication has certainly gone up ......Any advice?