Intellectual female seeks really affordable room

I'm a referenced, non-smoking EU female living in London since 2015 and holding settled status.
Currently looking for an affordable single room (£300-400 a month max, please don't contact me if your room is more expensive!) in SW London / Surrey / or other locations in the South of England and willing to help with:
-cooking and housework, or
-school runs and homework, or
-walking of little dogs, or
-(potentially) gardening in exchange for a commensurate discount on rent.
Since I don't go out at night I may also be useful as a presence for elderly people.

My interests include history, architecture, writing, poetry, cycling, classical music.
Lifestyle: I spend most of the day on my laptop, cook simple healthy meals and don't invite friends.

Kindly refrain from asking adult services, I am asexual and not interested at all.
Move-in date is flexible. Please reply with a brief outline of your situation. Thanks.