Stick with it!
You just have to look through the threads to see that there are many people who are also struggling to adapt, its normal, natural, and totally understandable.
Get out and join some clubs and societies, see the towns near you, play some sport or see some films or something. Gather some experience and observations that you can share.
Then book some Skype time with your family and you will have some things to share enthusiastically with them. When you see how proud your nephews are it will help. You will be an amazing role model for them, work hard and you can achieve great things like uncle wartortle, have a fab university experience, get a great degree and a great job....
You can send them postcards, they dont need to say much, your nephews are still young and will appreciate a short funny story from you, even just a quick note to say you have a lecturer that looks like Wolverine, or someone found a mouse in their welly, or something, do you see what I mean, you can maintain a great relationship with them by staying connected like this. Then you can spend time settling in knowing that they will get your note in a day or two and laugh and talk about how fab you are and how its awesome that you have done so well.
Chin up, thousands of people are feeling just like you right now. Thousands did last year too, and the year before that....and things improve, emotions settle and it all turns out cool. Throw yourself into it, its getting better each day just let it in.