First of all I want to commend you for your courage speaking out and reaching out for help. I sure know this is an awful situation and you are dealing with it the best you can.
Secondly, only you know what is good for yourself and the circumstances you find yourself in. You owe nothing to anyone, be that a justification on how you decide to procede or explaining your feelings.
Everything you feel right now is VALID. Even you being worried about this other person's wellbeing which only shows that you have a good natured heart and want the best for others.
From what I read you have a good understanding of your own emotions and what your needs are right now.
I want you to focus on that. E.g what do you enjoy doing? Drawing, music, writing? Whatever it is I want you to make a priority to keep your mind busy with other things. This will hopefully ease your anxiety and can naturally cause you being less and less available via WhatsApp to respond to unwanted messages.
It's also great you have reached out to a friend, the more you talk about this the easier it will get to bear this situation mentally.
If at any point during tonight the thoughts become unbearable please call the Samaritans on 116 123. You don't have to feel suicidal to call, might feel awkward at first if you have never done it but you can do this anonymously.
Again getting your thoughts out in the open and talk might help make you feel calmer and gives you also an opportunity to talk through any course of action you want to do or not do in the future.
Lastly you can have a look on the Scottish Social Service Council (SSSC) for information about raising concerns regarding conducts of workers. This can also be done anonymously I believe. Obviously that's information for Scotland, even if you live outside Scotland I'd email or call them and they might be able to direct you to the appropriate social service council that oversees your support service.
Telephone number for SSSC: +443456030891
Raising concerns
You are brave. You matter.
Never forget that.
All the best OP, take care of yourself you got it!