I have been refused US visa twice.The first was B1 follow by F1 3weeks ago.I am 31 and an African,a Cameroonian.I am holder of Bachelor of Science in Nursing since 2012 and I wanted to re-study Nursing in USA enrolling for an Associate degree in Nursing.The US Embassy Yaounde is tricky.

Please what should I do to overcome my situation?
Can a US Immigration Lawyer handle it online?