Hey,

I've had quite a lot of problems during my PhD including supervisor problems (which are now hopefully been resolved) and as a result have struggled with anxiety and depression.
I'm currently 13 months in but have been plagued with negative thoughts from very early on, including:

1. I will never get enough data to be able to write a thesis at the end and 4 years will be wasted
2. other students are far better in all aspects (presentations, experimental design, confidence, just everything!)
3. my work is rubbish and well below standard
4. I really can't see anything working out, I don't trust that " data will come "

these thoughts have had a huge impact on my PhD, and completely crippled my confidence resulting in me avoiding presentations/ chances to talk about my research, freaking out about attending conferences and generally withdrawing and been frustrated with my project. Even when my thesis committee say I've got good knowledge and made progress etc I just don't believe them.
As a result of my panic I often rush through experiments, not wanting to take time to optimise them and then when things go wrong I take it as a huge blow.

I'm currently on leave due to these issues, but upon return I really need to deal with them. Any advice is much appreciated !

Sorry to hear what you are going through.

Very briefly, I would go to your GP and ask to be referred for counselling. Counselling should help you deal with your low self-esteem and confidence. Once you have sorted that out, your problems should resolve.

maybe you will feel better when you hear my story. I study from home. i have been studying 8-12 hours a day six days a week which means that i work hard than other students. However, i didn't get that far as i should. a phd student normally take 6 to 12 months to get into their confirmation. Yet, it has been 14 months and i am still not get there yet. one of students who i know in our department, super lazy and only submit a very simple and brief research proposal. but she got her confirmation in 8 months.
i don't think my situation better than you at all. at least, you already come to the point of data collection. i am not even pass my first step yet. Anyway, hope my story will make you feel better.

** part one
Everyone is panicking at the beginning!! I hated presentations!! I was always thinking I don't have enough results, or someone will ask me a question that I could not answer, or I will not be able to explain what I'm doing... and so on. The best recipe to overcome this 'fear of exposure' is to expose yourself. Just step out of your comfort zone! I know it's hard. I went through it as well.

A year ago my supervisor (who is not longer my supervisor and I'm very happy about that) told me to do a presentation on local conference in my field. Everything would be perfect apart from the fact that some of my data did not make any sense. I was trying to an advise from him, but he was never able to have a useful conversation about any staff that I was doing during my PhD (that's why he is not my supervisor anymore). I still had to present!! I was terrified. I asked a few close friends from my research group to go through my slides and I practised my presentation in front of them (but not my supervisor). The night before when I was practising, I bursted into tears (that was like a panic attack) because I had all those negative thoughts!! I told myself 'Ok it's just 15 min presentation and then we will see'.

**part two

I was a nervous, but I presented and it was actually very good. I spoke after the presentation with some people (some other PhD students and some professors) they all said my work is good, no one has criticised me, people were nice, of course they made some suggestions (which was very good).

The best thing now is that I'm not afraid anymore of public speaking about my research!! You should not be afraid off because there is nothing to be afraid off! No one will eat you. When people see some mistakes, they usually gently and politely mention that.
So you should go to conference, group meetings, any kind of exposure and start talking to people about what you are doing.
Maybe don't do a oral presentation on the biggest conference straight away, but start with the poster, or just even a group meeting presentation is a great start. People are there to advise you.

I also think is a good idea to see a counsellor about your anxiety and start MEDITATION and SPORT

I started a blog about my struggles during PhD and I've written about dealing with difficult supervisor or depression during your PhD studies. Is a very good way of releasing your feelings, so I would highly recumbent everyone to start one !

** part three

Depression and anxiety is very common in academia, so don't ignore it!