Honestly, stress may be the trigger. As can a diet that is high in carbs and processed foods. So, you might want to modify your diet - increase protein and cutback or eliminate altogether processed foods. You might also want to consider that you may have had latent Herpes that has been triggered due to the stress. I would go to the doctor now and get tested. If you do have active herpes, you will need a c-section. I'm not trying to scare you, but the majority of the adult US population has been exposed to genital herpes and are asymptomatic,
Also, I learned the hard way with my first child that stress at this time isn't good for you and it's also not good for your baby - I was trying to get a project at work finished and working long hours. In the end, I had high blood pressure and had to be induced - my son had a very difficult delivery - cord around his neck and he was in ICU for a while.
So, with my 2nd son, I just took it easy the last trimester and worked with my boss and a reduced work day schedule and doing some work at home. You might talk to your doctor about going on leave early. It will cut into your (paid) time off after the baby, but in my experience this small financial setback is so worthwhile in the bigger picture. My second son was an extremely healthy baby. Also, a stressed mama can have difficulty with breastfeeding and it actually impacts the quality/make-up of the breast milk. Stress is actually one of the biggest contributors to poor health.
I realize you're likely a very independent person, but now is really the time to be asking for help. You're going to also need lots of it after the baby is born, so lining up support from friends now is really, really important.