Never been so afraid in my life..

Today has been one of the worst days of my life... the day started off great until me and my SO got into a minor arguement... One thing lead to another and he ended up pushing me with our son in my arms and he choked me... All over me wanting to keep MY car so I could get out of the house today.. (he took that as me wanting to go cheat) I'm a stay at home mom, so I wanted fresh air... After everything happend he ended up calling in to work so he could "fix things".... I told him I didn't want to be with him anymore, and he said then leave... Mind you, our son is three months old, and I have no where to go because I quit my job to stay home with him. He has been walking around and talking like nothing happend today.. I'm just in shock because I never in a million years thought it would be like this... He's thrown things and broke stuff, but never hit me.. he promised to never hit me... I'm 19 and he's 23.. so we're still pretty young. He's all I've ever known, and the only person I talk to, so this is my venting... I just don't know what to do.. I love him so much... Being a teen mom is already something people criticize, but even more single mothers... I don't want to be a failure... I want my son to have both parents...

Sorry for the long post...

Side note... here's my Fortune cookie...