I think maybe it is, Sunblue. I do think you prophesy pain, disappointment and eternal victimhood for yourself. (I don't think you should feel guilty about it, though. But if you came to agree with this, if I'm correct--and I won't swear I am though today I'm too wonky in my own head to write this other than rather bluntly--I believe your life would begin to change.)
I may be wrong but since you've invited opinions I will give mine (and I'm irritable with myself, tired, and fighting a ghastly procrastination battle at the moment--please forgive that and sort of drain that out of my tone if you can. I do want to help you).
I think adolescents often make choices that are about their transient sense of social identity or pleasing friends. They have completely different inner lives and motives than one might think they "should".
And, they often seem amazingly incapable of viewing adults as people who can have hurt feelings, or who exist for any other purpose than to orbit them.
Your niece's may be a natural and temporary form of narcissism...it's an emotionally adolescent state. Hopefully in the future she'll be able to express gratitude to you. Or perhaps if she senses how much you need or want her to be grateful, that may have made her feel uncomfortably beholden so she didn't want to publicly thank you. And may never. So perhaps, "hopefully" is an unwise suggestion. Probably much much healthier NOT to hope, in that sense, for her approval or recognition. Just decide for YOURSELF that you've been a very good aunt, and release that gift to the universe.
Ultimately, you might feel happier if you help people only when it makes you feel good about yourself and by yourself, regardless of others' gratitude. It's the old "my family are turnips but I want them to be rabbits so I will continue digging up turnips" kind of thing. When pure altruism won't satisfy (you're human too!) help people who DO seem to appreciate it. That would likely be found outside your family, from what you've always posted about them. Is there something volunteer that you could feel excited about? Maybe not something religious that one does for saintly reasons, but something that meets a serious and practical need?
I think what I hear in your posts is that you are focused outside yourself, and wanting to do things that will make people divine or do or give you the love you are fantasizing about, and then when they do (which never happens), you will be able to feel good about yourself.
The only way to feel good about yourself, imnho, will be to love yourself (this is made up of real thoughts and real actions, it's not an abstraction), learn basic assertiveness (there are workshops) so you can say No (boss, brother, niece, anyone you need to say No to) so you begin to undo your habit of collaborating in creating a persistent illustration (to yourself) of yourself as a victim.
It does not matter if you have done this for a very long time. For a long time, it worked for you. But if it ceases to work, and you are motivated, you can do something very new for yourself for the rest of your life.
I don't think you can do it alone. I couldn't, anyway. Therapy and group work and community of my own outside the crushing marriage and family relationships were the things that gave me eventually enough hope and courage to love myself. (Took me a lot of work and time to seek out and build those things, they didn't appear on a tray. I had to intentionally expose myself and give myself and extend myself ad risk myself. And some didn't work out and I got hurt and learned and tried again. It's been a long process and I think that's now completely okay with me. I have gotten so I'm less crushed, or even when hurt--I of course still can be--I recover my self esteem faster than I used to. I used to be so devastated by every hurt that I was paralysed. I think that's why I always respond to you. I recognize that pain.)
You talk repeatedly of people taking advantage of you. They cannot unless you give them permission, either overtly or passively. That's where I think the prophecy happens.
How about a new prophecy? YOU WILL BE HAPPIER once you take responsibility for your healing and wholeness and decide to create your own happiness, not dependent on others' changing, suddenly "valuing you". It is very hard work and you can't skip the painful stretches of healing. But if you will do it, you will be happier. I would swear that on my life, Sunblue. When the notion that you can value and be pleased with and respect and protect yourself, or that it can become a baseline you return to consistently even after the disappointments of life...when that notion becomes real, it is lifechanging. In the best way.
I think we are supposed to do this. Self-loathing and self-pity (I am expert at this) are not our natural states. And we can overlay those mental grooves and thought habits with new, life-appreciating ones.
Stop being Cinderella. But stage your own balls.
And to start, I'd like to suggest that you praise and value and respect and love and feel proud of yourself for the fact that after all your terrible struggles about it, and your despair, and the times when you felt it would never ever happen, you struggled and got and kept a job. This is NOT a small thing you accomplished. It was very hard for you. I respect you tremendously for doing that. It was so hard.
Now, with pressure from boss...perhaps this job is STILL a great accomplishment, or it's a place where you can learn and experiment with healthy assertiveness. So you are not working so much overtime. You really can learn all sorts of good strategies for remaining valuable to your employer while still learning to create new boundaries there, and removing the Cinderella name-plaque from your desk.
There are so many books, articles, teachers, processes, groups, healing work opportunities, that can help you feel such warmth and pleasure and gratitude for being yourself. That's what I prophesy for you. I would love to have the gift.
But it only matters whether you do. Whether you have faith.
Or will search for it.
with love to you,
Hops