Braxton hicks or contractions?

I'll be 20 weeks in 2 days with my 4th baby. The past few days I've been having what I think is braxton hicks but they are getting uncomfortable. It's happening at least 2 in an hour right now. I have so much stress on me, I'm worried it's affecting my baby. I never experienced this with my other 3 babies. So I'm not sure what to do, or how to handle this. I also have been way over doing myself but I have 3 children my husband is recovering from a broken femur surgery and I'm his main caregiver, and obviously exhausted from being pregnant. I just don't want to lose my baby.. please any advice would be great. Also, I have a doppler baby's heartbeat is still around 150's.