There isn't much in Epicurean texts regarding pain. Here are some further thoughts on the subjective perception of pain.
Thinking of how there could be gradations or varying levels of pain, that range from mild discomfort to very painful (in the body)
1) a bearly noticeable feeling of discomfort
2) a slight feeling of pain
3) a moderate feeling pain
4) a strong feeling of pain
5) an excrutiating feeling pain
(or 1 -- 2/3 -- 5 --7/8 --10 on a scale of 1 to 10)
But for mental pain there are emotions and feelings which feel unpleasant, and the worst ones involve both the mind and the body (such as extreme anger, fear, or panic).