Can you tell me which branch of military I will fit into?

[go-go girl]

Due to the economic not improving I might have to join the military to get a stable job after graduate college with a Bachelors degree. I used to do a lot martial arts as kid and teen but I really looking for something that keeps me up on my toes. I do not mind roughing it at especially since I am female and all. I want to do something that has good impact on people around me. Knowing that I am helping the bigger picture of protecting people. I have been told by some people I am on tough cookie. However, I do not know which branches I should look more into. Also I am 4 '10'' which maybe a problem in some branches. Can you please tell me differences of the branches and what not? Thank you!
I looked up the height for almost all the branches I am ok with height ..I just lose some pounds.