How can I manage braxton-hicks contractions?

Abdominal support. By definition, braxton-hicks contractions are painless and do not lead to early labor. There is not much you can do to make them go away. Some people find an maternity abdominal binder helpful.
See your md. Depends on what you mean. You should contact you md to be sure they are indeed braxton-hicks and not preterm or actual term labor.