I did my masters a year after my undergraduate degree, and then continued on to my PhD, so you could say I do not have much experience. Things still went ok, I applied for a PhD in a good university and was awarded full funding, a world famous professor in my field offered to supervise me. But since I started he has been quite strict and too busy to offer any advice. I became more timid in my writing and am constantly stressed. At the end of my first year I mentioned wanting an academic responsibility, like TA work etc, my supervisor agreed but later changed his mind, leaving me no time to find something else. So the second year began with zero chance for work experience. (I did my undergraduate degree in another country so it prevents me from teaching here at undergraduate level.)

Then a new student started, someone who has a decade of work experience and who constantly brags about being old friends with our supervisor. And our supervisor started spending time with this new student, introducing him to people, giving him all sorts of responsibilities. This new student has also been openly hostile and competitive towards me, constantly mocking my lack of connection with our supervisor and brags about his plans of taking over every academic duty our supervisor can offer, Based by my supervisor's comments on his pre-PhD work experience, I feel like no matter how much I try, I am not good enough.

I can't help but feel bitter and am also constantly worried that I will never get any work experience or and proper supervision or recognition, probably barely finish my PhD, with no chance of finding a decent job. I can't talk to my supervisor about it. I can't request another supervisor since this one is very well-known in the field and no one in the department would agree to somehow offend him by taking me. I hate being in competition with this unpleasant middle aged student and not sure about what to do.

I was in a similar situation to you with my supervisor favouring his other student and I changed, it was the best thing I ever did. You'd be surprised how sympathetic other staff members can be towards you when you have such a big decision to make. I can't see other academics worrying about offending your supervisor. Academia is quite a selfish environment, and taking on a new student would benefit them and boost their own profile.

If you don't want to change, do you have a second supervisor you could use a bit more for help? That way you get the support but still get to keep your supervisor's name on your PhD.

I had two unsupportive supervisors, it was a difficult situation. Eventually I got a new lead supervisor, who was more supportive, and helpful in her way, but a very busy person, and not really the kind of supervisor whom I could drop in on for a chat. .

I realised I needed to make my own support network of other lecturers. It wasn't easy, as I felt I was damaged goods in my Dept after changing lead supervisor. However, I did volunteer on committees where I would meet academic staff, and I made a point of getting involved in one organisation in particular outside my institution. I also presented papers at internal seminars and external conferences.

My unsupportive supervisors are never, ever mentioned by me - I don't deny anything if asked outright, but I remain pleasant about them.

As for teaching, I got in touch directly with my head of department, which seemed to be the way things were done with regard to getting teaching work in my dept (your situation may be different).

Some people might suggest social media - build up a following on Twitter, blog, etc.

None of this is a fast fix - it takes time to build up a network. Nor is it a guarantee of success - I volunteered on one committee for several years, and still got passed over for a temporary teaching post by the committee chair in favour of his less-well qualified favourite. On the other hand, I owe my present temporary teaching post at another institution to contacts made on another committee. And my involvement in the external organisation indirectly resulted in a small, but very welcome, research award, as well as some book reviewing in a peer-reviewed journal.

Finally, if the other student is unpleasant to you, he must be feeling insecure in his position, and quite possibly threatened by you.

best of luck.