Should I Quit?

Okay so I found this job that I really like and I'm excited about, I just started and they really like me but I come home in excruciating pain every night from running around all day and they're really tough and you have to make a certain amount of money every hour to keep your job, It's about two hours there and back but it's been worth it till now and now I'm doubting and get this. 
I just had to call in because of a family emergency, my grandmother whose had to have tests down for irregular heart and labored breathing has had horrible chest pain all day and she's in the hospital and she's my best friend and I call in and my boss gets pissed at me "well we do keep track of this, is there anytime you can come in tonight?" And I'm driving right so I'm flustered I'm crying and I'm shocked by her coldness and she just goes "your going to be in on Wednesday right? " I tell her I will and she slams the fucking phone down misses the receiver obviously and then does it again to hang up on me. 
Like is this a sign here? Maybe I should just look for something else I mean this is bullshit right? And there have been other things as well, they don't train you except on an iPad and then they yell at you like you're supposed to know everything they preach about shoving a purchase down a brides throats till she gives in and not getting her dresses she wants but dresses like it that cost more. Not to mention not even a week in and because of this I was taking my customers to the register and letting others ring them up as per manager instructions and someone stole all my commission and nearly cost me my job on day three. 
Should I quit?