Hi sleepingplum
were you interrupted when posting? - do try again
I'll make some guesses in the meantime
we all lose our patience and tempers at times - don't be too hard on yourself - if you really feel you are out of control, as long as your father(in law?) is safe, just walk away and hide in another room for a while (bathroom may good - lock on the door and a good excuse to be there on your own), or make yourself a cuppa and sit and have some time out - if you have other family with you, let them know and let them look after for him for a while
long term, get some home care visits and day care if at all possible
if you are really out of control - leave the house - even if it's to stand in the cold to literally cool down - and if you are so worried call emergency services
if your father-I-l is out of control - please let him be if he is not a safety concern - don't try to physically intervene and don't argue - just leave him alone, maybe put on some soothing/favourite music - leave him for quite some time to settle or rage then settle
if he is violent towards you - get yourself somewhere safe and call the police - they are more used to these situations and how to deal well with them than we sometimes give credit for
apologies if I have misunderstood
let us know - I'm concerned
