I'm having a difficult phd, and sad to say now I've just started my 3rd year. I originally had interest in research but now I'm feeling completely lost. I entered with an interesting project in mind but project has been changed few times by my PI (just suddenly without much discussion) and finally settled down on 1. Because of my background, I initially had a project in mind which my PI approved but was changed because it was not in keeping with the lab's overall interest. The current project deviates very far from what I intended but I thought I would just persist and work hard and learn to 'enjoy in'. I've been trying to think of ideas and whenever I discuss with my supervisor, he comments that I do not 'understand' my project question well enough and asks me to think harder. Perhaps there is some mis-understanding from the beginning but after several discussions my supervisor seems to have lost the patience and things just seem to go down-hill then. The thing is I really want to ask more questions, share ideas, and engage in meaningful discussion with exchange of ideas. Each discussion pretty much always ends up in 'disaster', just a couple of minutes of 'updates' and just pretty much ends there. Next question is 'do I have data' and If not something interesting he just disappears or sulks. Any question I ask just ends up being 'fired back' and whenever I want to approach him just for some ideas, I will be told to come back later when I have all the plans 'laid out perfectly'. As a result, I just feel more and more anxious whenever I speak to my mentor. The more anxious I feel, the more likely I seem to say things wrongly. I am feeling sad all the time and wonder what I should do. Thanks for advice. I don't think he will listen if I even try to tell him how I'm feeling.

I think it would be a good idea to approach your university counselling service about this; they may have advice about planning how you approach your supervisor and managing your anxiety about his response and, in any case, feeling sad all the time is something you need to address with them. I also wonder if it would be worth writing down your questions for your supervisor and emailing them to him in advance of your meetings so that you don't feel anxious about formulating them 'in the moment'.