I agree with the last poster. It sounds so simple sometimes, but then doing it is another issue ...
Now I think of it as my being the spectator watching the violist on stage, instead of my being the violist playing the recital.
After a while it'll click, just keep up your effort.
One way that helped me tap into it better was noticing the things I do that keep me from inhaling temporarily, like speaking to someone, or chanting - I'm aware that I'm breathing out, and in-between phrases I'm breathing in.
Best wishes! There's no way to go but up