Thank you all for sharing!
I was inspired by your experience, Cariyaputta and what Lal wrote “Paying back previous debts is very important. These connections prevail though many lives, and can block the path to Nibbana.” and started crying and sat down to do metta directed towards all the beings in the 31 realms who possibly owe me anything, forgiving and releasing them. Then I started shaking for some while, letting it happen as I have done since it started happening occasionally since last autumn. I don’t know what it is but I feel I should just observe the shaking while it lasts.
One thing that I didn’t grasp fully was what “offering your merits” actually means and therefore I didn’t do it this time, but of course I would like to pay as much of my own debts in the future.