Hi Iwishiwasinfrance. I have read your post with my face like .
I must agree with many of the replies you have had here. Reading this it seems to me that you could not be worse off without him. You say you cannot leave because he could not afford maintenance ... well, he doesn't contribute now does he?
You and your father have maintained him. If it would be difficult without him (although I cannot, for the life of me, see what he contributes now) then your family sound wonderfully and would probably jump at the chance to help with child care etc. Is this not an option.
I actually feel quite worried for you. Tbh, in the future (and it will probably be soon) he will be in debt again. He will expect you to bail him out again. He will continue to negate all responsibility for everything because he has never had to pay the price for his stupidity.
I am sorry, but he will not learn anything while you are there. He sees your help as his right - where is the respect in that? He is an educated man, holding down a position of authority and responsibility - that doesn't make for a sensible person - as I think he shows at home.
Please take heed of the other posters here, who are much more eloquent than I. You need to seriously evaluate your relationship and situation. You would have support if you removed him from this situation and would get through it.
I don't mean to be rude but you do sound a little co-dependent. Are you sure you are not getting a little 'lift' from all this responsibility you have to assume? Not being rude but you do need to see that you are the coper, you are the manager, you are the one being responsible.
If necessary, take a few moments and go see a counsellor, maybe through your doctor, to talk about how you are feeling. They may help you get direction.
I wish you tons of best wishes, I hope you get this sorted. But in answer your post: no yanbu. He is taking the p*. The movie is merely the straw that broke the back of the camel