How should I tell my dad that I'm not his little girl?

I am the girl in the family I have my younger brother, plus 2 more younger brothers from our dad and my stepmom. I am a tomboy and my dad knows that but he still doesn't trust me. I mostly talk to guy friends than girl friends and my dad gets suspicious and thinks I go out to have sex or something, when he knows I don't. When I go to work he tells me he hopes I am going straight to work and not going to do stupid things. He got mad when I told him of course I go to work, making my own money is more important than doing things with a guy...I think he was mad because he knows he was wrong, he felt kind of guilty when I called him from my job to say I was on my way home.My brother and his gf had a pregnancy scare, along with my brother almost getting arressted and my dad didnt go over the top yelling at him like he yells at me, for the stupidest things like if I roll my eyes he says "Why the f*ck are you rollin your eyes" Each time I want to go to my friends house he acts like he doesnt even know her and he has met her plenty of times before. He tells me "Who is this friend, i don't her so just stay home and relax". I get I'm his oldest and only daughter but I feel uncomfortable when ppl tell me things like awww he does that because ur his little girl and I don't like being his little girl because he was hardly around and never does anything for me I just started really knowing him about 5 years ago when my brother and I had to move in with him and his mom, while our mother moved to N.C.