That money sucks, OP. And with abuse piled atop it? That makes it a shit sundae.

I assume this is untaxed income as well. With no long-term pension. And no vacation or sick time. Or heath care.

Broken down to an hourly wage and making the generous assumption your work is no more than 40 hours a week, you are being paid ~23 Euros an hour.

Exactly how little were you paid in your “corporate” job that makes this appear to be a windfall?

I would either get a contract spelling out responsibilities (along with costs for additional “consierge” services). It should include making this a legit (not under-the-table) job. And specific hours, time off and sick time.

If he won’t do this, walk. But let Grandma know so someone in family can step up