You know what - this IS the year that you will build confidence and get new friends.
Nothing bonds people like a shared experience, even a bad one. Get yourself to a cancer support group yesterday. A friend of mine (well...friend of the family, she's a lot younger than I am) had Thyroid cancer. Not only did she survive - her career is boosted (she was an oncology nurse of all things), she now has two daughters and she made new friends locally and nationally through the LiveStrong network (yeah, I know...it's fallen on dark days...but that truly was a good thing Lance Armstrong did).
Although I'm sure she would have preferred to never have had the cancer in the first place and I wish she hadn't either, her journey has made her a stronger, better connected and more rounded person.
Like you, I sometimes have trouble letting people in. But this year I've made great new friends through rugby. And a lot of that has been through standing with girls in freezing rain and covered in mud and blood and losing a lot. I don't want to be flip or compare voluntarily playing an insane sport to cancer - but just to say that if you can share adversity and experience and allow people to come into your life - they will.
And also to say, I'm really sorry you've had this diagnosis and will have to go through this. I'm also really sorry to hear about your eye, that is scary - and I hope that gets better soon!!!