Thank you for posting this question. I’m so sorry to hear what you’ve been through.
The latest research suggests that there’s a neurological basis for misophonia and that this has something to do with the way sounds are either received or processed by the amygdala.
So in that sense I think it’s likely misophonia itself exists independently of mental health conditions (i.e. is not caused by or co-dependent on a mental health condition).
However it is relatively common for the disorder to co-exist with mental health conditions both independently and with more of a tit for tat relationship. For example it could be argued that the stress of misophonia can amplify anxiety disorders.
Where you get this overlap (with misophonia heightening anxiety and emotion and as such interacting with a mental health condition) it must be very disorientating and confusing.
From personal experience, the effects of my misophodes are always immediate and directly related to the trigger sound or vision. For example the sound of someone chewing will instantly hurl me into it. There’s not really much leeway there and never a delay, but it does seem to be even more intense if I am already feeling stressed or anxious.
Other than a bit of anxiety and some very mild OCD I personally don’t suffer from a mental health condition (am I incredibly lucky in this regard) so it will be very interesting to hear what others have to say.