Does the location matter in a PhD choice? I am passionate about research, I believe in science and I get excited about it. For this reason, I have decided to start a PhD. Last year I started a PhD in a foreign country but it turned out to be unsatisfactory from different points of view - the work was poorly organized. The supervisor was not providing guidance and knowdlege and I decide to try to change the situation. I won other 2 position in Europe and this was a surprise for me, it means that people really see that this is what I really want to do. Having 2 options was not easy and in the end I decided to go in a very good university in Sweden with a very good project and a lot of industrial connections. My boyfriend is currently living there and he told me how well the PhD are structured in Sweden. I am very very sure that on the working aspect I will have absolutely no problems. I have a lot of fears when it comes to the weather. I have lived in central Europe and it was not sunny everyday and for me it did not matter. Soon I will have to leave my country for Sweden and I started to not sleep at night, to abuse a little bit of alcohol (I am ashamed of it, but yes) and sometimes I cry all the time saying that I do not want to spend my years there. When I think about the project and the university I am very very happy, when I think about the country less, because when I was there, I had not really a good feeling. I do not want to quit my second PhD. I want to start a new PhD being sure of what I am doing.
What should I do? It would probably mean that I will not have a possibility anymore and so I have to give up the idea of getting a PhD. I don't know why I changed my mind, if it is just fear or I really do not want to go.
Please, do not close the topic, I really need an advice. How much social life and location can make a difference in your life? I would like to hear some experiences.
Thank you!
I do not want to quit my second PhD.

It would be unfortunate if you needed to quit -- but not the end of the world.

I want to start a new PhD being sure of what I am doing.

In my experience, it is rare to ever be completely sure of what you are doing.

How much social life and location can make a difference in your life?

A lot.

What should I do?

Ultimately, only you can say.
That said, you've already accepted an offer in Sweden. You're very happy with the university, and apparently your boyfriend is there. In your shoes, personally, I would go and try to make the best of the situation. It won't be for the rest of your life, and if things go badly then you can reevaluate later.