Do you think he was worried that you'd not bother looking hard for a job? So telling you to pay half was his way of pushing you, making sure you knew he expected it?
Tbh, you have a gut feeling for a reason. Your issue here is not what you pay - if you can take him on face value about it changing back to what makes you comfortable. Your issue is him not caring enough to understand why it upset you. Maybe you're just feeling vulnerable about moving generally... a good man will listen to those fears.
Have you made a proposal yet?
Here's what I'd do:
Work out your new earnings (are you temp now?)
Work out outgoings, ignoring luxury food and sky (if you genuinely wouldn't have it)
Work out proportional amount
Then compare it to your old outgoing.
Maybe you earn 1/3 of the household, and the outgoings are £1000. So your share is £333.
But - you've given up free (?) rent and used to have outgoings of £250
I'd propose in that case that you pay him either what you paid out before, or your proportional share, whichever is lower. With a bottom level that you don't COST him. So if your parents paid for everything, and you had no outgoings, you'd have to pay exactly what it costed for you to be there.
At this point, he is cost neutral.
You are either neutral, or gaining.
If you gain, agree with him that it's put against your loans to reduce them quicker. Then, when they're paid off, the extra goes into a separate account which you will keep in your name, to start to build a "maternity leave" fund for both of your benefit.
If he won't discuss it, or disagrees - end it.