You're obviously better off away from this nasty person and his family.

Certainly you are not a slave for him and his family, and you have no obligations whatsoever to your in-laws.

There are plenty of people and agencies in this country who will be able to help you (as thankfully you are starting to discover).

Don't worry too much about your ILR at the moment, just take things one step at a time and start to build a new life.

We all make mistakes.