They can help you deal and process and learn to live with what happened.
Even though you don't know what happened, you have to find a way to live with this situation, deal with the emotions and move on.
Thats where professional help comes in.
Your fears are do not sound as if they decreasing, but spiralling out of control.
A professional can help you learn techniques to stop this pattern of thinking. Despite you not knowing the actual facts of what happened that night.
You need to learn better ways to think.
I have bad thinking styles too - I am very black and white in my thinking.
I tend to dwell on a negative and then imagine all sorts of scenario's. I come to really dramatic outcomes with my thinking.
Maybe it might help if you google 'unhelpful thinking styles' and see if you can identify with them.
As for your digestive system, stress and worry can have a major impact on it. You worrying will not be helping.
I wish you the best
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