I am kinda new to ST (mostly lurk) so I hope I don't step on any toes by adding my input - but what jumped out at me most were those two statements bolded above. I don't know if I am just supremely lucky or what, but I don't have any friends that would even remotely resent me or feel jealous of me for anything good that I have done, only pride and support. I guess I can imagine people in your life that you don't choose (kids' friends' parents, husband's friends spouses, etc), but so far in my life I have no one in my life that I would choose to tell stuff to that would then feel negatively towards me about it. Who are these people you are concerned about??
Also, it sounds to me like you are gracious and think about what other people may feel before you do or say anything, so I bet you err on the side of extra-caution for the most part, and if you let loose and talked yourself up more I bet you'd still not offend anyone. The right people in your life will support and be happy for you when good things happen. It's a good filter for selecting friends, I think.
It would probably help to think about 10 things you like about yourself and ponder them daily for a while, until you feel comfortable with actively liking stuff about yourself and not feel guilty about it. Matter of fact, I challenge you (and anyone else who wants) to list 10 things you like about yourself and/or accomplishments you're proud of for all of us to see and applaud!!! You go girl!