What's the WORST thing about your PhD topic?

In the beginning I had noone to talk to. Noone. I was describing the "problem" and I was getting responses like "you shouldn't get into this area".
Then I found some articles which were discussing exactly the same thing. I thought that I could use them to back up my observations.
Not a good idea. I got the "What makes you think that you will solve something that people with PhD in Mathematics have not been able to?"
My first degree is not in Maths. I told him that my entire PhD thesis will be on defending my viewpoint and I will hope that someone from another discipline will base her/his research in Maths on my findings and argumentation on the problem.

Until 5 days ago... what I need has been already created it was developed for a similar problem to the one I am obsessed with by a group of researchers, not in the UK, not in Europe, but in Australia and in China. Now I am focusing on the application of their research in my field.

So "the worst thing about my PhD topic" is not the topic, is that the people who work on this area are not on this side of the planet. For two years I am battling with this research question, pretty sure that I am on the right path, all but one academics that I have talked to were demotivating me. One had seen the problem because of her research but she had spoken to the "expert" from Oxbridge - who by the way dominates with his research the entire continent on what is doable or not in his area - who advised her to avoid this specific topic.

I think that I came with a lot of hope and ambitions on conducting research in England and now I see that it is governed by mediocre minds, at least in my research field.
I am sorry for the long post, but I was feeling like coming from another planet for long enough and it turns that the problem was not me.