I will try to make this short.
I'm 26 and had a long-term relationship with a man, Josh, of the same age since we were 21 (though we have known each other for seven years). We grew apart over the years of dating and were both unhappy, especially myself, and we ended the relationship seven months ago. After a few months of little contact, he's started calling and e-mailing me again to tell me that he wishes we could have worked things out. In our time apart, I have been casually dating a man, Kevin, who I really care for. I've tried to take things slow, as I know I'm still healing from my previous relationship and really need to focus on what I need to do to make myself happy. Kevin has been very patient and understanding. In response to Josh's attempts to reconnect, I have told him that I care about him but that I feel we are not right for each other. I have been putting off telling him about Kevin, though I had planned to do so soon. I don't know if that's the best move, but I feel it would let him know that at least for the time being, I am trying to move on. But yesterday, Josh informed me that he is to be undergoing tests because of symptoms that could be related to cancer. He's terrified, and I know he feels more comfortable talking to me than any of his friends. I am horrified at the idea of Josh, whom I love dearly but do not want a relationship with, having cancer. I feel I should be by his side and help him through this, even though I no longer desire to be his girlfriend. I can't bring myself to tell him about me dating someone else, especially not at this point when he is feeling so overwhelmed. I want to do what is best for him, and what is best for me. I really, truly love Josh, but not in a romantic way. But he was, and is, above all the person I would still consider my best friend. I feel my intense emotions of guilt over finding happiness with someone else, and over the end of my relationship with Josh, are fogging my ability to think logically. I don't know what to do. Do I stay by Josh's side and help him through what could be a life-threatening ordeal? Or do I count on his friends and family to do this, and continue with my new life? Should I be up front with him during this difficult time, or continue to keep my dating a secret?
Please help. I forgot to mention, I now live more than 1,000 miles away from Josh, had to move for work.
Thank you.

wow, what a rough situation to be in. Now first, you definitely need to evaluate yourself. Are you and Kevin in a relationship? Yes, then make sure your honest and up front with him about it all. Next, Josh, as horrible of a situation he may be in, there is nothing wrong with you explaining your situation to him along with even going to be by his side just so he knows how much you do care, but not in a lover fashion.....

If i were in your shoes, i would definitely be by my friends side if they were in need, but it wouldnt break a relationship im in.

Time to be strong. Follow your heart, and not your head...and it will be fine

I hope everything works out fine for all three of you...