I think you have PUPPs! I am very sorry if you do. It is, of course, not life-threatening, but extremely torturous. When you said you had it on your face, I didn't think that was it. But you described it as occuring along the jaw-line, which happened to me.
There was another thread about this which you should read. Apparently, people have much better advice to deal with it than I had. Basically, I just roughed it out. It was especially excrutiating postpartum for me. For whatever reason, the PUPPs became these pimple-like bumps all over my body (so far so normal) with puss and blood that burst out of them at the slightest touch after I had ds. I had these tiny scabs covering most of my limbs and back. MW said it continued postpartum because I nursed, but that when I weaned, it would stop. That wasn't good news as I planned to nurse a long time (and still do - ds is 18 months). It did stop though when ds was around 13 or 14 months. But at about a year of this, I broke down and saw a dermatologist who was clueless. He insisted they were the result of dry skin and prescribed hydrocortisone (sp?) cream, which I never filled because it did nothing for me. But I think it's unusual that my PUPPs lasted beyond postpartum and that most PUPPs goes away after giving birth. Anyway, good luck dealing with it if it is PUPPs, but I'm also hoping for you that that isn't it. Perhaps you're allergic to something.