Quote from RolfAccept what you cannot enjoy
This is very instructive to think about, and first I'd like to second what Cassius had to say.
As to the Tetrapharmakos... for me, there's a big difference between "what's bad is easy to endure" and "Pain does not last continuously in the flesh; instead, the sharpest pain lasts the shortest time, a pain that exceeds bodily pleasure lasts only a few days, and diseases that last a long time involve delights that exceed their pains." (St-Andre) The first is a pablum, but PD04 offers a guideline with which to examine our pain.
A better way to say this might be that the first offers a way to distract the mind, the second offers a way to engage the senses to arrive at a deeper truth. And, really, this is at the core of Epicurean philosophy.
Relating to this is the experience of intensity, duration and location, which is expressed in other PDs. Examine where the pain resides. Is it physical, mental? Where? Is it an "organic" sensation or a reaction to sensation (fearing, anticipating or dwelling on it)? Are there gaps? Can pleasure be found in the gaps? Can this pleasure be increased? Are there prudent ways to directly decrease the intensity of the pain? Can the pain be expected to subside at some point? &c... The feelings are two, not one, and both are guides to living our best lives.
Living as an Epicurist requires a generally unacknowledged degree of mental and physical strength: we're not offered formulas for living our lives, we have to come to an understanding that we thrive through asking difficult questions and facing difficult experiences. We don't try to cast them off as "indifferents", as some would have us do.