Inner knee pain can be so many things. I get it sometimes & I think it's related to my Sciatica. It's actually been bothering me the last couple of days. I think I either overdid it stretching or pulled something while cleaning. Sometimes tense muscles can cause it, too. I know it's hard, but try to ignore it. If it persists or gets really bad, see a doctor. But I think after a few days, it'll probably go away. Try not to worry about every little ache & pain -- give it time to see what happens. I'm telling you this because I've been going through the same thing.
I'm 35 & have the same worry about dying & leaving my family. But I think I'm finally realizing that it's really out of my hands. If I end up having something treatable someday, then I get that taken care of if I can. No point in the "what ifs" because it might never happen! I more or less fear the sudden/freak deaths (something you don't see coming) because I worry about my family. BUT the chances of this happening are so low & again, what good is worrying? Because if something does happen like that, there's no chance of preventing it. And I have no control over what goes on after I'm dead, so I can only hope that everyone is ok without me (which I'm sure they would be). We've gotta let these fears go!