Berk

I think it is a great moment for you to realize that you begin to adapt your new life. I am a first year of Ph.D. and my relentless mentor made me cry 3 times. I already went through a mental breakdown and actually yelled at my advisor during one of the lab meetings. Thank God everyday if you have a supporting faculty around you. I was a very successful undergrad and had an amazing master's experience, but I have lost all my passion and ambition in the Ph.D. thanks to my mentor. You will be fine but I won't. That's why I am doing my best to live this goddamn place. 
 
 
 

@Dalmatian Yes, I have had students cry in my office, usually in circumstances not unlike what you're describing. It happens. Not much you can do about an uncontrollable emotion that sweeps over you, so I'm glad to hear that your professor handled it well. 
@Berk Oh, that really doesn't sound healthy for someone in their first semester. I would strongly advise you to look for support elsewhere, be it through moving to another lab/supervisor or by simply finding a mentor who isn't your advisor. It can be an advanced student, a faculty member, maybe someone in a specialized support group (those exist!). But don't just keep going like this for too long, because you'll find it very hard to finish, and I'd personally question whether you should. A PhD is not worth 5 years of suffering. 

I think it is a great moment for you to realize that you begin to adapt your new life. I am a first year of Ph.D. and my relentless mentor made me cry 3 times. I already went through a mental breakdown and actually yelled at my advisor during one of the lab meetings. Thank God everyday if you have a supporting faculty around you. I was a very successful undergrad and had an amazing master's experience, but I have lost all my passion and ambition in the Ph.D. thanks to my mentor. You will be fine but I won't. That's why I am doing my best to live this goddamn place.