I can't tell you what it is... Therefore you would prob consult a doctor...
In my case I just can tell you that I was going to literally any kind of doctors which are about that region and they all couldn't find anything but all were mentioning that I shouldn't take it as hard as I do - psychologically speaking...
So this is also described in TCM and eastern beliefs as a heaviness of the heart...
For me I had this symptom about years!
Was literally freakin out too!
But I think it comes along with underlying issues - psychosomatically!
May you wanna think about why you wanted to take part in that ceremony etc...
Your mood may be calm and stuff but there is sometimes more undertheground....
Other than that considering you were takin ayahuasca and had a difficult fearful situation, may you were afraid of your well being as you said he was somehow violent...
You couldn't move may you were afraid of not be able to protect yourself, which could be a general issue... so it was for me....
Medicinally speaking there are tons of issues which share this symptom... but may you have just had lain uncomfortably while sleeping... you have a cough... whatever
It's the job that's never started as takes longest to finish. - J.R.R. Tolkien
How long will this last, this delicious feeling of being alive, of having penetrated the veil which hides beauty and the wonders of celestial vistas? It doesn't matter, as there can be nothing but gratitude for even a glimpse of what exists for those who can become open to it. - Alexander Shulgin