Feeling useless when it comes to other people's tests etc

I'm beginning to feel like I'm the last person who anyone should go to for support for their own tests and such.  Today, a coworker came to chat with me saying she was going for a lump removal (excisional biopsy?) and I'm not sure I was much help.  I find it hard to do the whole "everything will be ok" as someone who's been on the other side of this and knows its not always ok (although I very much hope it is not the case for this woman, just don't need to risk scaring anyone) and find I also have to hold back from asking the barrage of questions about their symptoms because I know a little too much.  I listened and told her I hoped everything would be ok. 

I also find I worry excessively if friends or family tell me about tests they have coming up.  I not only worry about them because they are my friends and loved ones of course, but I do the same obsessive Dr. Google crap that I would do if I was going through the same tests myself (I don't tell them this fyi).  It is really hard for my mind not to spin off in wild directions and that means I can't concentrate and sometimes can't sleep.  What this also means is that I end up obsessing again about my own breast health and start poking at myself constantly. I remember reading an article a couple of years ago about a survivor who found herself almost unconsciously doing BSE's in meetings, while driving, or sitting in front of the tv etc.  That's also me, although it mostly picks up around these times and of course my own test-times.   Had a few breast pokes in the washroom today at work already. Obviously I'm very suggestible.

Am not trying to make anyone else's experiences my own or all about me.  I wish I was more able to be there for people without feeling so messed up.