My Pitbull attacked me... PLEASE HELP i dont know what to do.?

I have a 3 year old Pit-bull and I need help. About 3 weeks ago he attacked my mom's dog and I broke up the fight; my moms chihuahua was not hurt because I grabbed him from my dogs mouth before damage was done. The tension between the two is known and for that reason we separate them on different levels in my house, some how my moms dog wonder down which prompted the fight. Long story short I know my Pit is dog aggressive and really only likes my boyfriends Pit. I can deal with all this, but he just recently took his aggression to a whole new level and attacked me a few days go. By attack I mean he growled, lunged and pushed me down ( i was sitting on the floor) for no reason. He didn't bite me, but since this happen I have become scared of him. I feel like he gets this stare in his eyes the past few days and he is just acting very different. I don't know if he senses my fear for him now or what. I am so lost as to what to do! This is tearing me apart because i love this dog so much and just 3 weeks ago before all this happened he was my little snuggle bug and i trusted him with my life 100%. What do i do? How do i help this situation? How do i begin to fix this situation if I'm now scared of him? Please, there is noting more i want to do than to hug him and be normal.