Planning on coming out to my dad today...

Ok, so I've already told him I'm not straight. What I haven't told him, is that I have a girlfriend. We have been dating since early September officially, and non officially since the end of summer.I didn't tell him because I wanted to make sure i knew this was going to be serious before I told him, and also because I'm scared since he's the only person I have left since my mom kicked me out of her house.The one thing he can't stand is lying, and I've definitely been telling him I'm with other friends out late at night, and not this mystery girl that he knows nothing about.Any advice or kind words would be appreciated. I'm gonna need some luck :p