I know there are probably a million PhD students feeling the same way - but I feel like I am on the edge of a nervous break down.  I am in the third year of my PhD, I have made zero progress in well over a year.  None of my experiments work.  I spend most of my time feeling depressed and phaffing on line.   I have never been to a conference.   Outside of the lab, I am not particularly depressed, I am successful socially and in sports and I leave my worries in the lab.
I am used to being quite successful at my work so this is really driving my insane.  I have been stuck in a rut for over a year now, I need something to start working, but I have gotten to a point where I just don't care anymore and I am just trying to hang in there and weather this whole experience out.  But that is not going to get me a paper for sure.  I need motivation, I need advice, any advice, please.   :(

Hello, am so sorry you are feeling this way. I felt this way too (and still do at times, even though I have submitted - now I'm in a postdoc and the pressure of that and probably not taking a break is not doing me well).

How is your relationship with your supervisor? If you have already talked to them about the experiments, can you tell us more about what has been their response? Are they caring, sympathetic, offering guidance/advice at all to help you to get through, or have they been relatively unsupportive? Do you feel comfortable to talk to them about how you're feeling? I know it will be hard, but I really think it could help, and that you need to change something of what you are doing right now, because continuing in this way will only produce the same results and feelings that you are experiencing. Talking to your supervisor, telling them completely honestly where you are at in terms of progress, etc, will allow the opportunity to create a realistic plan for how to get past this.

Please post back if you can so we can keep working on ideas :)

Hi Powerin10

You situation is almost similar as mine. I'm in my final year, should submit my thesis in 4 more months, feel like I haven't done anything at all and still have a lot to do. Sometimes I feel that I won't finish this PhD. I had a nervous breakdown few weeks ago, things have not been so good since but at least I feel a little better now.

I truly understand the "don't care anymore" feeling. First of all, focus on feeling better to regain the perspective. Meet the counselors, take some break, go for a holiday- leave all your work and you'll return fresh. Secondly, ask for help. Does you supervisor help much? Or are there any other lecturers or post graduate in your lab/ department? Or if you are same as me- not so helpful supervisor/ no one to discuss with in the lab/ dept, maybe you can join forums asking a particular topics e.g. C++ forum etc. Talk about you research to anyone- your supervisor, labmates, friends etc (but be careful not to expose too much). Although they may not give any useful input, you'll organize your thoughts when you are trying to make them understand about your research. Sometimes it even feel less stress after talking to them. Thirdly, just try to gather whatever you have got and write papers from it, then send the papers to conferences and journals. At least you can get some replies or feedback on how to improve or go on from the reviewers. Or it is even better if the papers are accepted.

If the problem really couldn't be solve as you initially expected, is there any way that you can work around it? Or change something?

Of course you have been through lots of ups and downs, but remember all the times when you had overcame the problems that you thought were impossible before. You had been successful many times and it is not impossible that you'll be successful again this time. (gift) Just try to keep going until the end.
Hopefully I'll be successful too...